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THOMAS CHARLES BRIDGES

THE SKY RIDERS

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A STIRRING TALE OF ADVENTURE ROUND THE WORLD


Ex Libris

Serialised in The Children's Newspaper, 27 Sep 1919-14 Feb 1920

First book edition:
George G. Harrap & Co., London, 1921

Collected in The T.C. Bridges Adventure Book
George G Harrap & Company, London, 1933

This e-book edition: Roy Glashan's Library, 2021
Version Date: 2021-01-04
Produced by Keith Emmett and Roy Glashan

All content added by RGL is proprietary and protected by copyright.

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Illustration

"The Sky Riders,"
George G. Harrap & Co., London, 1921


Illustration

"The T.C. Bridges Adventure Book," with "The Sky Riders"


Illustration

Title Page, "The Sky Riders"


Illustration

Headpiece from "The Children's Newspaper" serial


TABLE OF CONTENTS

Chapter I
Chapter II
Chapter III
Chapter IV
Chapter V
Chapter VI
Chapter VII
Chapter VIII
Chapter IX
Chapter X
Chapter XI
Chapter XII
Chapter XIII
Chapter XIV
Chapter XV
Chapter XVI
Chapter XVII
Chapter XVIII
Chapter XIX
Chapter XX
Chapter XXI
Chapter XXII
Chapter XXIII
Chapter XXIV
Chapter XXV
Chapter XXVI
Chapter XXVII
Chapter XXVIII



CHAPTER I
THE MODEL

THE sharp trill of an electric bell cut through the quiet warmth of the pleasant sitting-room of "The Cot," and Cyril Hamer sprang from his chair.

"It's Dad, Stella," he said breathlessly. "He told me he'd ring when it was ready."

Stella Earle, a slim girl of fourteen with a great mass of ruddy golden hair, had jumped up as quickly as Cyril himself.

"Can't I come too?" she begged.

"Wait a minute, Stella. I'll ask him," answered Cyril.

Stella looked just the tiniest bit disappointed, but sat down again obediently. Cyril gave her one little nod, then was out of the room and up the stairs three steps at a time. On the upper floor he tapped at a tall, white-painted door.

"Come in," answered a deep voice, and Cyril entered.

Coming out of the dark passage into the big loft, the hard glare of the electric lights was so blinding that Cyril stopped short, and stood blinking in the brilliance. A big, loosely-built man with a keen, clever face stepped forward with a laugh.

"Yes, it's a bit brilliant, Cyril, is it not?—but for once I have turned on all the lights. It's worth it, lad—don't you think so?"

"She's finished, Dad?" exclaimed Cyril breathlessly.

"Yes. I put the last touch to her not five minutes ago. Now tell me what you think of her."

Cyril did not answer at once. He was staring at the beautiful object which hung from a great cross-beam overhead. It was the model of an airship—a long, slim, dainty thing gleaming silvery grey in the strong light.

He drew a long breath.

"What a beauty!" he said at last. "What perfect stream-lines! Dad, she doesn't look as if she belonged to earth at all. I believe if you opened the window she'd fly clean away."

Martin Hamer laughed softly.

"That is just what has struck me, Cyril boy. Do you know, I really believe that I have at last found the perfect lines for a dirigible. Remember, too, that her frame is not aluminium, but all steel, that she is far more rigid than anything of the kind ever yet produced, and that she, the full-sized ship which I shall build, will stand driving through any storm that blows. What is more, she can alight on hard ground more easily than any 'plane, and can be anchored out in the open with perfect safety. Given the power—and that is what I will give her—you could cruise the world in her. You could go from here to China without a stop, you could visit the lonely Poles, could cross the snowy heights of the Himalayas, or lay bare the secrets of the unknown Bolivian swamp forests."

His fine face lit up as he spoke, and his eyes—which, in spite of his forty-eight years, were clear and blue as his son's—glowed with enthusiasm. Sixteen-year-old Cyril found himself gazing at his father rather than at the model, and thinking, not for the first time, what a wonderful man he was. Cyril had the most enormous admiration for his father. The two had always been perfect friends, but since the death of Cyril's mother, three years earlier, they had drawn even more closely together.

"Dad," broke in the boy, as his father ceased talking, "Stella is here. May I bring her up?"

"Do!" replied his father heartily. "She won't understand it as you do, but I'm sure she will like it."

Cyril rushed off, and a minute later the door burst open again.

"Here you are, Stella," said Cyril eagerly. "You're the second person to see it. Isn't it wonderful?"

Stella Earle's big blue eyes widened as she stood gazing at the model.

"The new airship!" she cried. "Oh, it's wonderful! It looks like a great fish ready to dart away. Let it loose, Mr Hamer. It just wants to fly."

Cyril laughed delightedly.

"Exactly what I said, Dad."

Mr Hamer smiled indulgently. "We shall have to give her power before she can fly. Stella, I am going to ask your uncle if he will let me build a big ship on these lines. Then you and I and Cyril can fly all over the world if we want to."

"You are going to Mr Carne, Dad?" asked Cyril quickly. His bright face had become suddenly grave.

"Yes, Cyril. I work for him. Surely he has first claim?"

Cyril did not reply, but turned to the girl.

"Stella, I promised you should be back by seven. It's nearly that now. I must take you home."

"Back soon, Dad," he called over his shoulder. He kept his word, and barely twenty minutes later was in the loft again, to find his father still gazing at the model.

"Supper's nearly ready, Dad," said the boy. "Come on."

The elder man reluctantly tore himself away, and presently the two were sitting at the plain but excellently cooked meal which old Mrs Vince, their housekeeper, had laid for them.

"Dad," began Cyril at once, "I wouldn't go to Mr Carne if I were you."

"Why not?" asked the other quickly.

"Because Mr Carne is as hard as nails, and I don't believe you will get your proper share of I he profits from him."

Mr Hamer's eyes widened.

"Surely you don't want me to think that he would not deal honestly with me, Cyril?"

"Oh, he is straight enough," replied Cyril, with a shrug. "But he's what they call a business man, and that means that he is out to get every penny he can."

"That may be so," said Mr Hamer gravely. "At the same time, since I am in his employ, I feel that it is only right that he should have first call on my new invention. If he will not help me to build the full-sized ship, then I will go elsewhere."

Cyril did not attempt to argue further. He knew his father too well.

"All right, Dad," he replied gravely. "Do as you think right. Only promise me one thing. Patent your drawings and specifications before anyone else sees the model."

Mr Hamer nodded. "Yes, Cyril, I will do that. I will post them to-night."


CHAPTER II
'CHILLED STEEL CARNE'

"WHAT do you want for it?"

They called Mortimer Carne 'Chilled Steel Carne,' and the name fitted him exactly. He was hard as iron, and his voice was like himself—strong, harsh, and rugged. For some five minutes he had been examining the new model minutely, and no point had escaped his small but sharp grey eyes.

"I do not wish to sell it outright, Mr Carne," replied the inventor. "My idea was that you should let me build the airship herself in your works, in return for a half-share in the profits."

"Out of the question!" snapped the millionaire. "Absolutely impossible! I am full up with contracts. It would be two years before I could spare men or space for a job like that. Even then as likely as not it will prove a failure, as so many similar models have proved in the past."

Martin Hamer flushed slightly. "I will stake my reputation that this will be no failure, Mr Carne," he answered quietly. "I have spent years upon it. The whole idea is absolutely new—not only the shape, but also the internal tension-steel construction."

"That is as may be," said the other coldly. "But I have had more experience than you in similar inventions. The model has its points, I will admit, and that is why I will make you an offer. I will give you a cheque for 500 down for your model and all rights."

Mr Hamer looked distressed. "I am sorry, Mr Carne—I am very sorry—but I could not accept such terms. I do not wish to part with all rights, and I am anxious to build the full-sized machine at once."

"I'll say seven hundred and fifty," said Carne sharply. "That is my final offer."

Mr Hamer shook his head. "I am very sorry indeed, Mr Carne, but I cannot sell."

The big man was not accustomed to opposition. Besides, he realized much more clearly than he had allowed that this model was a startlingly new invention.

"You'll sell or be sorry," he retorted harshly. "I should advise you to remember that you are my servant, and that you depend upon me for the very bread you eat and the roof that shelters you."

It was the wrong tone to take with a man like Martin Hamer. Quiet and gentle as he was, he was no coward.

He threw up his head. "I call that an ungenerous taunt, Mr Carne. You should bear in mind that I give you my work in return for your money."

"I can do without your work much more easily than you can do without my money," sneered the other. "I can get a dozen draughtsmen as good for less than I am paying you."

Mr Hamer's eyes flashed, yet he kept his temper. "In that case, sir," he answered quietly, "I suggest that you should do so without loss of time."

Mortimer Carne glared for a moment at the man who had dared to beard him.

"I will!" he said, in a voice hoarse with anger. "Take yourself and your beggarly model off at once, and never dare show your face in my works again. And when you are starving don't come and beg of me—that's all I have to tell you."

With that he swung round and stamped out of the place.

The other stood perfectly still, listening to the heavy tread descending the stairs. He drew a long breath.

"What will Cyril say?" he murmured, with drawn face. He paused. "And Stella?" he added sadly. "What about Stella? It will be cruel to break their friendship, yet now that this has happened Carne will never allow Cyril to see her."

It was as hard a task as Martin Hamer had ever had to tell his son how he had lost his place in the Ajax Works. The worst of it all was that he had no private income, and that his experiments had run away with most of his savings.

"So you see, Cyril," he ended, "we must leave the house at once, take a cheap cottage, and live as quietly as we can for the present."

But Cyril was not in the least dismayed.

"Right you are, Dad! But it will only be till you get some one to take on the airship."

His father looked at him steadily.

"You don't blame me, Cyril?"

"Blame you!" cried Cyril. "My dear Dad, how could you possibly have done anything else than what you did do?"

"But you begged me not to go to Carne."

"Oh, I know him a bit better than you! You see, I've learnt a lot by being so much with Stella." His face fell suddenly. "I say, I suppose he won't let Stella come here any more?"

"I am afraid he won't," replied his father sadly.

Cyril bit his lip. He was very fond of the pretty niece of the Steel King. He and Stella had always been tremendous chums.

"That's poor luck," he said; "but never mind. Once we are on our legs old Carne will come round quick enough. As for Stella, even her uncle could never make her go back on us."

He paused.

"But what about Tim?" he asked quickly. Mr Hamer shook his head.

"He will have to go. I can't afford even his wages. I'll ring and tell him."

He touched the bell, and almost at once the door opened, and in came the quaintest-looking youth you could see in a day's walk. He was only just five feet high, and until you had had a good look at him you would have said he was about fourteen. But his queer, wrinkled face was that of a man of twenty. He had eyes as green as a cat's, a snub nose, a shock of close-cropped, bright red hair, and a wide mouth, with an excellent set of white teeth.

As a matter of fact, Tim M'Keown was about seventeen, but had no notion of the date of his birthday. He had never kept one at all until that ugly accident in the Ajax Works, when he had been taken in half-dead and doctored back to life by Mr Hamer and his son.

"Ye was wanting me, sorr?" he said, looking keenly at Mr Hamer.

Mr Hamer cleared his throat.

"Yes, Tim. I—I have some bad news to give you. I have lost my post in Mr Carne's works. It's a very serious loss to me, for I have nothing besides my pay, and no other position in sight. To put it plainly, Tim, I cannot afford to pay even your wages, and I am afraid you must try to find another place."

Tim stared as if he could not quite believe his ears.

"Me find another place, is it?" Then his face fell visibly. "Is it that you're sick of me, sorr?"

"Don't be foolish, Tim. No one could ask for a better boy. It is simply that I cannot pay your wages."

Tim looked straight in Mr Hamer's face.

"And is it for that I'd be laving you?" he demanded. "Is it me that would be taking another man's money when ye made me? Sure now, so long as ye can give me bite and sup, here I stay, so let there be no more talk about it."

There was more talk, but Mr Hamer was quite unable to change Tim's decision. Suddenly a bell tinkled through the house, and Tim hurried off. Cyril looked at his father.

"I knew he wouldn't go, Dad," he began triumphantly.

Before anything more could be said, the door opened.

"Misther Kent to see ye!" announced Tim.

Mr Hamer started violently.

"Kent," he repeated in a voice of extreme astonishment—"Bertram Kent—impossible!"

The new-comer laughed softly. It was not a pleasant sound.

"Yes, Mr Hamer," he said in a curious, purring voice. "Bertram Kent, and no one else."

For some seconds the two men stood facing one another. Mr Hamer seemed still to be unable to believe the evidence of his eyes.

Cyril was also staring at the new-comer. He said to himself that he did not like the look of him. Kent, indeed, was a curious figure. He was a powerful, heavily-built man about forty years old. Thick black hair contrasted with a dead-white face, while his eyes, under dark brows, were like pools of ink. The jaw was powerful and he had a thick fleshy nose. It was a strong face, but not a pleasant one.

"You never expected to see me in England again, Hamer?" said Kent at last, in that odd, slow, purring voice.

Mr Hamer pulled himself together.

"That is true," he answered. "As a matter of fact, I never expected to see you at all again. I heard you were dead."

"Ah, Carne told you that!" replied Kent, with a twisted smile. "I let him think so, and I should like him to remain under the same impression. But, see here, I have called on business, and I had better go straight to the point. It has come to my ears that you have invented a new dirigible, and that you have offered the model to Carne, who has refused it."

"How did you learn that?" demanded Mr Hamer. "From Carne?"

A curious gleam came into Kent's sunken eyes.

"I told you that Carne believes me dead. I have never exchanged a word with the fellow since you know when," he answered, and his voice had an ugly note in it. "It does not, however, matter to you where I obtained my information; you will admit that it is correct."

"It is," allowed the inventor; "but still I should like to know what it has to do with you."

"A good deal—and with you, too. I know your work. I know it is generally good. At the same time, I am aware that you have not the money to build the ship yourself. I came to tell you that if the invention is as good as I hear I can introduce you to a man who will finance you in building the full-sized dirigible."

"Who is the man?" asked Mr Hamer.

"That I will tell you when I have seen the model."

Mr Hamer hesitated. He did not like or trust Kent, and that for very good reasons. Yet he believed that the man had rich acquaintances, and he was desperately anxious to get the work in hand. At the same time he remembered that, as he had already patented his model, there could be no harm in letting an outsider see it.

"Very well," he said at last. "Come with me."

Cyril, who already had conceived anything but a liking for Kent, stayed where he was. He had some time to wait, for it was nearly an hour before he heard the two come down again. The front door opened and closed, and Mr Hamer came into the sitting-room.

"Who is this man, Dad?" asked Cyril gravely.

"Bertram Kent, you mean?"

"Yes."

"He was Mr Carne's partner ten years ago. The two had a desperate quarrel about something. Carne declared openly that Kent had robbed him, and, instead of suing him for libel, Kent left England, and was said to have gone to Morocco, where I heard he had died."

Cyril grunted.

"I don't like Mr Carne, but I shouldn't wonder if he was right this time. I don't care about the looks of this chap Kent."

"I can't say that I like Kent myself," agreed his father. "Still, this is merely a business arrangement. Kent gets his commission, and there his interest ceases."

"And what is the name of Kent's friend, Dad?"

"Gaunt, of Gaunt and Marvin. They are a Bolport firm, he tells me, and are interested in aircraft. Kent is going to Bolport on Monday and will see Mr Gaunt."

Cyril looked doubtful.

"Do you think he really will, Dad?"

"Why should he not? He will get his commission if the business goes through."

Cyril nodded.

"Well, I hope it's all right," he answered, "but personally I shouldn't put much faith in Mr Bertram Kent. Anyhow, if Gaunt does see the model, I'm sure he'll jump at it."

"I hope he will," said Mr Hamer, who still looked troubled. "You don't think it can have done any harm, Cyril, letting Kent see the model?"

"Of course not, Dad. And now let's get on with our packing. Remember, we move the day after to-morrow."

They were very busy all the rest of the day, went to bed dog-tired, and both slept like dormice. Cyril was a little late for breakfast, and when he hurried into the room was astonished to find his father not yet down. He went out into the hall, and called:

"Dad! Breakfast's ready!"

There were hurried steps on the stairs. Next moment Mr Hamer was in the hall. He was pale as death and panting for breath.

Cyril stared at him in dismay.

"The drawings!" gasped his father. "The drawings! They have been stolen. Some one has broken in through the roof of the loft during the night. The safe has been burst open and all the designs and plans have been taken."

For a moment Cyril could not speak. The shock was too great. But he quickly recovered.

"Is that all they got? They didn't take your new motive-power papers?"

"No. They were in my desk downstairs."

"And the model—is that safe?"

"That has not been touched."

Cyril looked immensely relieved.

"Then why worry, my dear Dad? You have patented all the plans. No one else can use them at least, not for sale."


CHAPTER III
CYRIL TAKES CHARGE

MR HAMER looked up from the pile of papers which littered the table in front of him. Three months had elapsed since the burglary, but nothing had been discovered as to the thief.

"I have given up all hope of hearing from Gaunt, Cyril," he said wearily.

Cyril, who was at one side of the clean but shabby little cottage room, busy mixing something with a pestle in a mortar, looked round.

"I gave that up long ago, Dad," he answered. "And if you ask me, that fellow Kent has never been near Gaunt. Or, if he has, he has simply queered our pitch. It's three months and more since he came to us first, and since then it has been nothing but promises and excuses. Kent's a bad lot. That's the long and the short of it."

The lines on Mr Hamer's tired face deepened. Things had not been going well with him since he had left Carne's, and money grew scarcer every day. He was very anxious and troubled.

"But why, Cyril—why should Kent queer our pitch, as you put it? Whatever grudge he has against Mortimer Carne he has nothing against us."

"I don't pretend to know what his game is," Cyril answered. "But there is something going on behind the scenes. Of that I am perfectly certain. Where has Kent been all this time? He has been away from Marchester nearly the whole of the past three months. He has only been to see us twice, and his letters come from Bolport and all over the place.

"I've been thinking over it a lot," continued Cyril, frowning. "It seems to me that Kent has been doing his best to keep you from getting into touch with anyone who would take up your invention."

"But why, lad—why?" repeated his father.

Cyril laid down the mortar and turned round, facing his father. The light showed his cheeks thinner than they once used to be. He looked older, too. They were very near the end of their resources, and even food had been none too plentiful of late.

"I'll tell you what it is, Dad," he said sharply. "It was Kent that stole our plans, and he hopes to starve us out, so that in the end he can get them for nothing. That's what it is. I'm sure of it. Why didn't I think of it before?"

His father listened with wide-open eyes. Mr Hamer was one of those men who never thought evil of others, and Cyril's sudden accusation absolutely shocked him. Yet he could find nothing to say, for all of a sudden it dawned upon him that what the boy had said was indeed true.

Before he could find words, there came a peal at the bell, followed by a loud knock at the door.

The Hamers had no servant now. Cyril ran to the door. The moment he unlatched it it burst open, and in, like a tornado, rushed Mortimer Carne. He paid no attention to Cyril, but dashed in upon his father. His great face was crimson with rage, and his grey eyes burned like molten steel.

"You villain!" he roared, shaking his ponderous fist in Mr Hamer's face. "You villain! What have you done with Stella?"

Mr Hamer merely sat and stared. He was far too amazed to be able to answer this amazing accusation.

"Speak!" shouted the ironmaster. "Speak, or—"

Cyril sprang between them. His eyes were blazing.

"What do you mean, Mr Carne?" he cried. "What do you mean by talking like that to my father?"

Mr Hamer recovered a little.

"If you would kindly explain," he said coldly, "then perhaps we could reply to you."

"You pretend ignorance," retorted the other, who was beside himself with fury. "You'll tell me next you don't know that Stella has been stolen away!"

"I do tell you so. This is the first I have heard of it," replied Mr Hamer, and there was that in his voice and manner which impressed Carne, in spite of himself.

"Stella stolen!" cried Cyril in real distress. "When? How?"

Carne was silent a moment. His cold eyes roved from father to son.

"Is it possible that I am mistaken, after all? Can it have been some one else? But no. The airship was yours. I could swear to it!"

Cyril lost patience.

"For goodness' sake, explain, Mr Carne. What airship are you talking about?"

"Your father's, you brat! Though I had but a glance at it, though it was already almost dark, I could swear to its shape."

Cyril looked him full in the eyes.

"And how do you think we could have built it?" he asked bitterly. "You know the state of our purse as well as anyone."

"I know you could not have done it, but I imagine you sold your rights."

Cyril started. "Dad," he said sharply, "it's Kent!"

The name struck Carne like a thunderbolt. He quivered, and sank down in a chair.

"Kent!" he gasped. "Bertram Kent!"

"Yes. Bertram Kent came here three months ago, and saw the model, under promise of finding some one to finance the building of the new ship," replied Cyril rapidly. "He went away, and that same night the plans were stolen. As Father had patented the designs, we did not worry greatly, but now—now I begin to see light."

The ironmaster gave a deep groan.

"I, too," he said heavily. "Bertram Kent hates me bitterly. Years ago he swore he would get even with me. Without a doubt it is he who has stolen Stella."

"It was Kent. Not a doubt of it," declared Cyril. Now that the ironmaster had calmed down a little, Cyril could find it in his heart to be sorry for him, for the unfortunate man looked desperately miserable.

His big face was flabby, his eyes bloodshot, and his hair, generally so smoothly brushed, stood on end, giving him a curiously unkempt appearance.

"Yes," Cyril went on. "Kent must have had the idea in his head for a long time past. Before you came in, Mr Carne, I was just saying to Father that I did not believe he ever had any idea of finding us a purchaser. No, he only came here so as to look round, and find where the plans were kept. Then he stole them; he has had the new ship constructed somewhere in secret, and used her to carry off Stella. But tell us about it. When did he do it, and how?"

"Little more than an hour ago. I had come out of the works for tea when I noticed an airship moving rapidly away in an easterly direction. Something about her shape seemed familiar, and, going back into my office, I got a pair of glasses and had a look at her. Then I saw that she was on the lines of the model which your father showed me three months ago, and I wondered who had put up the money for building her."

He paused a moment.

"I walked across to my own house, and the first person who met me was my butler, Pitts. He looked frightened. 'Miss Stella can't be found anywhere,' he said.

"I rushed up to the schoolroom, then to her own room. She was nowhere to be found. We searched the grounds. At the end of the garden, near the paddock, we found Miss Sheringham, Stella's governess, lying insensible. She had been drugged. We got her round as quickly as possible, and from her I heard the truth at last.

"She and Stella had seen the airship descend in the paddock behind the trees which cut it off from the road. Naturally they had gone to look at it. At once two masked men rushed at them. A rug was flung over Miss Sheringham's head, and this stifled her screams. After that she knows nothing, but she has no doubt that the scoundrels carried off Stella in the airship."

"And what have you done?" demanded Cyril. "What steps have you taken?"

"None," said Mr Carne confusedly. "I came here at once."

"What! You have not sent anyone after Kent?"

"How could I? The police can't catch an airship."

"You should have called up the Holton aerodrome. They would have sent a 'plane up."

"I never thought of it."

"Then let us do it at once. It may not be too late."

He ran out. His father and Mr Carne followed.

"It's too late, I fear," said Mr Hamer gravely. "It is quite dark."

Carne groaned. It was true. The thick gloom of a dull October evening hung over the town. An airship might have passed overhead without anyone being the wiser.

They hurried after Cyril, to find him already at the telephone. The answer was that it was too thick for any 'plane to go up. Cyril did not despair. He got on to the trunk line and called up Hendon. There it was finer, and they promised to send up a machine.

Then Cyril got on to Scotland Yard, and asked the police to warn all parts of England, especially the south-east. The boy simply took charge; he fairly amazed Carne by his resource and quickness.

The hours dragged by. The Hendon 'plane saw nothing, but toward midnight they had news from Brighton that the sound of engines had been heard overhead.

"Then Kent's crossed the Channel," said Cyril decidedly.

"Gone to France, I suppose?" said Carne despondingly.

"No; France is far too civilized," replied Cyril quickly. "He's gone a lot farther than that. Spain more likely, or—" He started. "Didn't you say he'd been in Morocco?"

"Yes," Carne answered. "He went there when he and I broke up."

"Then that's where he's gone," declared Cyril.

"What, would she fly as far?" asked Carne.

"It depends upon her size," Mr Hamer answered. "If she was built to my specifications she could easily fly to India or the Cape without refilling her tanks."

"Great heavens! Then this scoundrel may be carrying Stella into the very heart of Africa for all we know," said Carne unhappily.

"It's quite likely," allowed Cyril. "We shall have to follow."

"How?" asked the ironmaster.

"Build another dirigible," replied Cyril briefly.

Carne stared at the boy.

"I never thought of that," he said slowly.

Carne turned to Mr Hamer.

"How long would it take?" he demanded.

"That depends upon the number of men. If you put on your whole force she could be ready in a month."

Carne considered a moment. Then he brought his great fist down with a crash upon the table.

"We'll do it!" he said.


CHAPTER IV
THE BUILDING OF THE "AVENGER"

NEXT day passed, and the wires were busy. Wireless messages, too, were being flung broadcast. About midday news came that early in the morning a large dirigible had been seen passing over the Pyrenees at a great height.

"I was right," said Cyril. "Kent is making for Africa."

Carne groaned again.

"My poor Stella! What will they do with her?"

"She'll come to no harm," said Cyril stoutly. "Kent will hold her to ransom. We shall hear from him sooner or later."

Carne ground his teeth and muttered something under his breath. Cyril felt that Kent would have a poor time of it if Stella's uncle ever got him into his clutches.

Now that the first shock was over, the ironmaster pulled himself together. That afternoon he began to mobilize his forces. Then he went and found Mr Hamer, who was busy in his shabby little workroom.

"Get out your plans, Hamer," he said, "and let's have the model. I mean to build the new airship as quickly as my works can do it. She shall be called the 'Avenger.' I don't care if I have to put every man-jack in the place on the work, or to scrap every contract I have in hand. Get to your plans. You shall have no reason to call me a niggard, and if we find Stella, I'll make your fortune for you!"

Mr Hamer looked up.

"I am already busy with the new drawings," he said quietly. "The model is at your service. As for making my fortune, I am going into this not for your sake, but because my boy and I love Stella."

Carne scowled.

"You talk very straight, Hamer," he said; "and I dare say I deserve it. But so long as you give me your help, that is all I want."

He went away, and that evening he came in again, bringing an agreement drawn up by a lawyer.

"Glance through this, Hamer," he said gruffly. "And if you think it is fair, sign it."

Mr Hamer read it through.

"It is more than fair," he answered. "If you will ask your secretary to come in and act as witness, I will sign at once."

This was done, and next day work began in earnest. The whole resources of the great Ajax Works were put at Mr Hamer's disposal. What was more, Carne insisted on the Hamers moving from their cottage into a house of his own close to the works. He got back Mrs Vince to do the housekeeping and cooking, and made everything as easy as before it had been difficult.

Once he had made up his mind, the way he drove forward was amazing. Shifts worked night and day, large premiums were offered to the men themselves for quick work, while the very best artificers were collected for each special job.

Mr Hamer, up to his eyes in work, did not notice that Cyril was away half the time. He never saw Cyril and Tim M'Keown drive off very early each morning in Mr Carne's own car. He would have been startled if he had known that the place they went to every day was Holton Aerodrome, where the pair were both learning how to handle not only dirigibles, but 'planes.

Both learned wonderfully quickly, but Tim fairly amazed his instructors by his cleverness. Inside ten days he could make a landing like an old pilot.

"Faith, 'tis the finest game in the worrld!" Tim told Cyril. "I feel I can make thim things do anything except talk."

"You're a holy wonder, Tim," answered Cyril. "Captain Mackenzie says he never saw anyone take to it as you have done. And you're going to be worth your weight in gold when we really get to work. You know the dodge we're going to try?"

"To take a 'plane along wid us, ye mane?" said Tim.

"Just so. She is being built for us at the Nolan Works. Mr Carne is having it done. She will fold up and stow in quite a small space, but she'll be able to do 120 miles an hour. If we once sight Kent's ship, he'll get the surprise of his life."

Tim chuckled.

"'Deed, and I'm thinking that black-hearted fellow will be sorry for himself before we've done wid him. And where do you think he's hiding himself, Misther Cyril?"

"Somewhere in the Sahara. That's my notion," replied Cyril. "You know it's not all desert by a long chalk. There are oases, as they call them, places where there are wells and springs and trees. Some are as big as an English county. My notion is that he has established himself in one of these."

"'Tis a mighty big place to look for him," remarked Tim thoughtfully, as he stared at a great map of North Africa which hung on the wall. "'Twill be like looking for a needle in a rick-yard."

"Not a bit of it," answered Cyril confidently. "Remember we can see hundreds of square miles at once, and a dirigible can't be hidden behind a rock or under a palm tree."

While they talked the door was flung open, and Mr Carne stalked in.

"Where's your father, Cyril?" he asked, so sharply that Cyril realized at once that there was something wrong.

"In the inner room. What is it, Mr Carne?"

"I have heard from Kent," replied the big man, and his voice was hoarse with anger. "A letter has just come from him."

"Where is he?"

"The postmark is Algiers. There is no date, and no trace, of course, as to where the scoundrel is really hiding himself."

"And Stella—what does he say about Stella?" asked Cyril eagerly. "Is she safe? Is she well?"

"So far she is safe," answered Carne, in a voice which shook in spite of all his efforts to control it. "But, oh!—"

He stopped short. A gust of rage seized him, and he stood shaking his clenched fist, unable to speak for very fury.


CHAPTER V
KENT'S THREAT

CYRIL waited until the ironmaster had calmed down a little.

"What does he say?" he asked.

With fingers that shook, Carne unfolded the letter.

"I won't read you the first part," he said, in a voice that he strove hard to keep steady. "It is one string of abuse. The gist of it is this. Kent offers to restore Stella for fifty thousand pounds in cash and all rights in your father's airship."

"He doesn't want much!" said Cyril scornfully. "And if you refuse his terms, what then?"

"Then—this is the awful part of it. The fiend declares that he will leave Stella in the hands of a certain savage tribe to be brought up among them—as a savage. And Cyril—he says that they are cannibals."

Cyril went quite white. The thing was such a horror that he could hardly bring himself to believe it. Little Stella, with her dainty ways and golden hair, to be condemned to such a fate! It seemed hardly possible that any man could be such a brute. He felt sick.

"Kent's worse even than I thought him," he said at last. "It's simply too beastly to be thought of."

"Ah, you don't know him as I do," Carne answered hoarsely. "The man is as bad a lot as ever I have come across in all my fifty years. He had been robbing me for months before I found him out, and doing it in the meanest and most cunning fashion. I don't mind telling you now that he very nearly ruined me. When I discovered what he had been at I took the law into my own hands, and thrashed him till he could not stand. Then I kicked him out. He swore then that he would be revenged upon me, but never did I think that he would wreak his spite in such a hideous fashion."

The big man dropped in a chair, and covered his face with his hands. Cyril saw his great shoulders heaving. He stepped across and laid a hand on his arm.

"Don't give way, sir," he said quietly. "Remember that Kent is not going to have things all his own way. Our airship will be larger and far more powerful than his, and there is no place in the world where he can be safe from us. Remember, too, that we shall be ready to start in less than a fortnight."

Carne looked up.

"You're a good fellow, Cyril," he said, "and the more I see of you and your father, the more sorry I feel that I have treated you as I have done."

"Don't think of it again," Cyril begged him. "Dad's forgotten it, and I'm sure I have."

"But I shall never forget it," answered the other sadly. "If I had accepted your father's first offer, Kent would never have got hold of those plans, and Stella would not have been kidnapped."

"Then Kent would have found some other way of getting even," said Cyril. "It's no use looking back, sir. What's done can't be changed, but it can be remedied. We must push on as fast as we can."

"Yes, yes. We must do that. Let us go and see how the work is progressing."

Carne rose as he spoke, but Cyril stopped him.

"May I have a look at the envelope of Kent's letter, sir?" he asked.

"Yes, of course. But why?"

"If we could find out where the paper was made or bought, it might help," said Cyril. "We don't want to miss any possible chance of discovering where Kent is hiding. We suppose it to be the Sahara, but it might not be, after all. There's a lot of unknown country in Arabia, for instance."

"I'm afraid the envelope will not be of much use," replied the other. "In all probability, Kent took it from England. Still, if you think it is of any use to you, take it and welcome."

He handed it over, Cyril put it carefully into his pocket-book, and the two went off together to the enormous shed which housed the "Avenger."

By this time the skeleton of the airship was complete, and lying there under the powerful electric lights she looked gigantic. As a matter of fact she was not as big as the latest naval airships, being less than four hundred feet in length. Yet, looking at her frame, Cyril felt that so far as power and stability went, there was no comparison.

As Mr Hamer had explained, she was built on the internal tension system. This sounds puzzling, but is not so really. Every one is familiar with the wheel of a bicycle and there you have the internal tension system in its simplest form. The new dirigible resembled a series of gigantic cycle wheels of different sizes, each with the tyre complete, and fixed firmly upon a central shaft, or axis. The biggest wheels were in the middle, and the sizes tapered off bow and stern. The smallest were at the stern, not at the bow, for Mr Hamer had followed the old yacht lines—'cod's head and mackerel tail,' as they are called.

Carne spoke to a foreman.

"Yes, sir," answered the man. "It's all right. The fabric for covering her is all here, and the girls are working on it in the loft. We expect to begin putting it on to-morrow."

"That's good, Menzies," said Carne. "Has Mr Hamer been in?"

"Not once to-day, sir. He stays in that workshop of his all day and most of the night."

"Let's go round and see him, Mr Carne," said Cyril.

Mr Carne nodded and the two went across the yard. As they neared Mr Hamer's workshop they became aware of a sound like the rattle of a machine-gun, a constant, clattering roar.

"The new engine," said Cyril in Carne's ear. "He's trying it."

The other nodded, and they opened the door. It was no use knocking, the row was too great.

The large airy building shook with the tremendous rattle. Clamped to a bench was an aero-engine running full blast, and close by stood Mr Hamer, in his shirt-sleeves, watching it.

Cyril went up and touched his father's arm. Mr Hamer turned a face which, though thin and blackened with oil, was alight with excitement.

He pointed to the engine, then nodded quickly and switched it off. The silence that followed was startling after the deafening din.

"She works!" cried the inventor. "She runs perfectly! See here!"

He swiftly unscrewed some nuts and lifted out the cylinder.

"Look at it!" he said, holding it up to the light. "Clean as if it had just been put in, yet she has been running three hours on end."

"My word, that must be wonderful petrol, Dad!" exclaimed Cyril.

Mr Hamer laughed.

"Petrol! It's not petrol at all. This is my new explosive."

As he spoke, Mr Hamer dipped his hand into a bag which lay upon the shelf near the engine, and brought it out full of a greeny-grey powder, which had a faint iridescent sheen. It was firm and dry as gunpowder, but much cleaner.

Cyril stared. Though he was aware that his father had been making experiments with a new fuel for motor-engines, he had no idea that he had been successful. As for Carne, his face lit with excitement.

"A dry fuel, Hamer? Do you mean you can ran your engine upon this?"

"I have been doing it for hours past. This stuff has twice the power of petrol, much less weight, and stores in a far smaller space. And you have seen for yourself that there is practically no soot. Man, using this, we can take the 'Avenger' clean round the world without stopping to refill our tanks"

Carne ran his fingers through the stuff, and examined it carefully.

"Is it safe to pack and handle?"

"Far safer than liquid petrol," was the answer.

Carne stared at him.

"You're a wonderful man, Hamer. What do you call it?"

"Bless you, I haven't thought of a name," laughed the inventor.

Cyril cut in.

"Call it 'Stellol'!" he exclaimed.

"We will," smiled his father. "'Stellol' let it be."

"Let us hope the name will be a good omen," said Carne quietly.

But even he seemed cheered, and when he left the workshop Cyril noticed that he held his head higher, and that his step was lighter.

The news of the new fuel soon spread through the works, and the men, who had been working hard before, redoubled their efforts. It was marvellous to see how the great fabric of the dirigible grew under their hands.

Cyril, who had been busy with Tim, completing his flying course, came one day to his father, and asked for five pounds.

"I want it for a special purpose," he said.

Mr Hamer handed over the money without question, and very early next morning Cyril left Marchester and no one saw him again until about ten that night, when he came home very tired but quite cheerful, and went straight to bed. He never said a word to his father and Carne about his doings, but next day went back to the aerodrome and continued his course.

By this time the gas-bags had been fitted, the huge frame of the "Avenger" was covered, and the first dose of varnish was being laid on to the linen fabric.

"We shall be ready to start next week," the ironmaster told Cyril, with great satisfaction. "The engines are complete, and I have arranged for a supply of helium with which to fill her."

"You are going to use helium, instead of hydrogen?" asked Cyril.

"Yes. Your father advises it. Though helium gas has not quite so great lifting power as hydrogen, it has many advantages. As you know, it is not inflammable, so that cuts out the risk of explosion. In a country like Africa, where thunder-storms are common, this is a great advantage. For another thing, it does not leak so rapidly as hydrogen, nor does it expand so rapidly with heat."

Cyril nodded.

"That's good, sir. And what about a crew?"

"I have engaged four men. There's that big Scotsman, Mackenzie, my foreman. He understands dirigibles thoroughly. The other three are Carter, Vane, and Saunderson. With the four of us, that should be as many as we require."

"Four of us!" repeated Cyril. "Are you coming, sir?"

"Of course I am coming," replied the other sharply.

Cyril did not reply. Privately he did not think that the ironmaster would be of much use on such an expedition, but he was too wise to say so.

Another week passed, the engines were in their place, all was ready, and it was decided to take the "Avenger" for a trial trip.

Dragged carefully out of her great garage into the open, she was released, and at once rose steadily and majestically to a height of about five hundred feet. Then her engines were started, and she sailed away on a perfectly even keel. As she began to feel the full power of her six propellers her pace increased, and the air began to whistle past her. Mr Hamer sat in front of a board covered with gauges and dials, and Cyril, watching him, saw his thin face glow with excitement.

"Better than eighty," he exclaimed. "And in still air! It's a record for a dirigible, Cyril. We ought to be twenty miles an hour faster than Kent's airship."

At that moment Carne came up.

"A success, Hamer," he said.

"Of course she is a success!" answered Mr Hamer. "I told you that when I showed you the model."

"I know," replied the other. "Well, I only hope we shall be equally successful in tracking down this ruffian who has kidnapped Stella. But my heart fails me when I think of the enormous spaces we have to explore."

"Not so large, sir," said Cyril quietly. "You see, I know within a hundred miles or so just where Kent has taken her."

Carne's eyes widened.

"What in the world do you mean?" he demanded.


CHAPTER VI
THE START

IT was quite clear that Cyril enjoyed the sensation he had created. He did not answer for a moment, but stood looking at the two older men with a twinkle in his eyes.

"What do you mean?" repeated Carne explosively. "How is it possible to say you know where Kent is?"

"I don't quite say that, sir," replied Cyril. "What I did say was that I know within a hundred miles or so where he is; or, at any rate, was."

Carne's temper was always short. He grew angry.

"Out with it, boy! Sharp now, or I shall think you are playing the fool, and inventing a silly story."

Cyril's eyes flashed, and for a moment he was inclined to resent the rough words. But he remembered what Carne had suffered, and felt that he was to be excused.

"There is nothing wonderful about it," he answered. "You remember that envelope you gave me, Mr Carne?"

"The one from Kent? Yes, of course. But you are not going to tell me the paper was made in the Sahara?"

"No, sir. As a matter of fact, it was made in London. It was not the paper that put me on the track; it was something inside the envelope. There were two or three grains of sand."

"Sand!" repeated Mr Carne angrily. "You will find sand on any English beach, or, for that matter, in any roadside ditch."

"I know that, but it would be flint sand in one place, granite sand in another, and so on. I remembered a case where a criminal had been caught in Austria because there was sand in his boots, which was found in one particular place."

He turned to his father.

"You remember the day I went to town, Dad?"

"The day you got five pounds from me? Yes, I remember."

"Well, I used the money to go up to London, and there I called upon Sir Hereward Clyne, the great geologist."

A grim smile curled the corners of Carne's mouth.

"Of all the cheek!" he muttered; but Cyril went on as if he had not heard.

"He was very civil, especially when I told him about Stella. Of course, he'd read about Stella's kidnapping in the papers. Then I showed him the sand, and he set to work at once, and put it under a microscope. He went on examining it for ever so long, and I got nearly frantic with impatience. At last he turned to me, and said: 'This is very curious, and if you had not told me that it probably came from Africa, I should have said it was from Brazil. It is what is called monazite.'"

Mr Hamer nodded.

"Yes, I know. It is a rare substance, but is found in one or two other places besides Brazil."

"So Sir Hereward said, Dad. He looked it up, and found that there are small deposits in Russia, and that one is mentioned as occurring in the oasis of El Azek in the central Southern Sahara. So," he added, "I think it's likely that that is where Kent wrote his letter."

Carne drew his breath with a whistling sound.

"The boy has more sense than I, Hamer. It is not certain, but the clue is a good one—quite good enough, at any rate, to follow up."

"I think so, too," replied Mr Hamer gravely. "When do we start, Carne?"

"To-morrow night, if we can get our stores aboard by then, and if you are satisfied with the engines."

"They are as near perfect as they can be," answered the inventor quietly. "Then this matter is settled, and for the present we had better return to the shed."

All was ready, and under the white glare of the electric lights the "Avenger" hung poised, still held down by a small army of men who only awaited the word to let go.

Up in the central gondola stood Cyril and Tim looking down.

"It's a pity we're leaving by night, Misther Cyril," said Tim regretfully. "Sure, all the town would have been out to give us a send-off if it had been daytime."

"And the papers would have been full of it, and Kent would probably have got to know we were on his track," replied Cyril. "You may be quite sure he has his spies in England."

"Faith, I niver thought of that. Won't he be hearing, anyways?"

"He may. Still, the building of the 'Avenger' has been kept as dark as possible, and I'm jolly sure not one of the workmen would have talked—they were all too fond of Stella. The story given out is that the ship was being built for a foreign Power."

Tim nodded, and was silent for some moments. Then he turned to Cyril again.

"I'm wondering where this spalpeen Kent got his money from. He'd have naded a lot to build a craft like this, now."

"I've thought of that, Tim," Cyril answered. "He must have made it in Africa. There are treasures of all sorts in the heart of the Dark Continent—gold, for instance, and ivory."

"I'll bet he stole it," said Tim with decision. "But if he's got it, so much the better for us. We'll be helping ourselves afther we've finished wid him."

He licked his lips, and his small face was screwed up so comically that Cyril could not help laughing.

At that moment Mr Hamer shouted a sharp order. The moorings were cast off, and the big dirigible rose as steadily as a lift into the darkness of the night sky. A moment later and the deep roar of her six huge engines burst out. The immense two-bladed screws spun dizzily, and she began to drive forward.

"We're off!" cried Cyril eagerly. "We're off at last."

It was between twelve and one on a quiet, dull autumn night that the start was made. There is usually less wind by night than by day, which is one reason why dirigibles make a practice of leaving during the hours of darkness.

Cyril and Tim were far too excited to feel sleepy. They stood where they were, looking down at the lights of the big town across which they were moving at a steadily-increasing speed.

A 'plane leaps instantly into its stride, but a dirigible, with her great bulk, is like a liner. It takes some minutes before she attains her full speed, and for the moment the "Avenger" was not travelling at more than twenty-five or thirty miles an hour.

They were still over the town when the gloom below was lighted by a brilliant flash, and up from the ground rushed a great hissing stream of fire which darted straight toward the airship.

"What is it?" gasped Cyril; but the words were hardly out of his mouth before the blazing comet rushed past, so close that he felt the heat of it upon his face, and struck the vast body overhead.

A shower of sparks broke out and dropped downward, but up at the spot where it had struck a smouldering glow appeared upon the outer skin of the airship.

In a flash Tim was off. Cyril followed, but Tim was even quicker than he. Like a cat he went up the wire ladder leading from the gondola into the body, and vanished into the gloom.

The gas which raises a dirigible is contained in a large number of separate balloons, with air spaces between. It was into one of these spaces that Tim swiftly clambered.

As Cyril scrambled after, Saunderson, a lean, sinewy Scot, came hurrying along.

"Let me by," he snapped.

"Don't worry," Cyril answered breathlessly, "Tim M'Keown is nearly there."

"A lad like that! What good is he? Give me room. We'll be afire next thing."

"It's all right," came a shrill shout from the darkness overhead. "I've beat it out."

Down came Tim again almost as quickly as he had gone up, and with some difficulty managed to assure Saunderson that all was right. The three returned to the gondola, to find the "Avenger's" course had been changed, and that she was flying due east at great speed.

"What is it?" demanded Carne, who was very angry and upset. "What do these fools mean by firing rockets?"

"Not fools, I think, Carne," replied Mr Hamer, who had left his engines to Saunderson. "Knaves!"

"What d'ye mean?" demanded Carne.

"That was no ordinary rocket; it was a Congreve, one of those old-fashioned war rockets. It was meant to set fire to us. It would have done so had the balloonets been filled with hydrogen instead of helium gas."

Carne gasped.

"D'ye mean it's some trick of that fellow Kent?"

"That is just what I do mean," responded the other calmly. "Indeed, I have no doubt whatever that this was a deliberate attempt to destroy the 'Avenger' before she could start on her mission."

Carne's face was purple.

"The brute!" he said hoarsely.

"Come, now!" said Mr Hamer. "There is no need to get excited. The danger is past. We are now going much too fast, and we are also much too high for any second attempt to be made. And, after all, what else did you expect?"

"Y-yes. I suppose you are right," answered Carne, who was still very much upset. "But what troubles me is the fact that the scoundrel clearly knows all about our plans. Besides, he must have a great deal of money and friends here in England to have been able to make such an attempt."

"He must have had plenty of money to build the first dirigible," replied the inventor, as calmly as ever. "It is just as well to realize what we are really up against, Carne. Don't you think so?"

Carne nodded.

"I suppose it is." Then his heavy jaw set. "We'll make him sorry before we have done with him," he added.

Mr Hamer turned to Cyril.

"You and Tim turn in," he said. "Yes; I insist upon it. Remember that we must all keep ourselves fit for what is before us."

Cyril never dreamed of arguing when his father put his foot down, and he and Tim went off to their hammocks. By this time the "Avenger" had risen to the three-thousand-foot level, and it was bitterly cold. They rolled themselves in their blankets, and, in spite of their surroundings, were soon asleep.

It was a ray of blinding sunshine striking his eyes which roused Cyril, and he sat up so sharply that he nearly fell out of his hammock. Then he swung out and sprang across to the window. Above was blue sky, below blue sea. During the night they had ran out of the fog and mist into fine, warm weather. Ships, looking like toys, crawled far beneath, and many miles to eastward a faint range of blue heights rose above the line of the horizon. Cyril was staring at these when there was a step behind him, and, looking round, he saw his father.

"Where are we, Dad?" he asked eagerly. "What coast is that?"

"Spain," answered his father; "the engines are working even better than I had hoped. We have been doing at least 120 miles an hour. At this rate we shall sight Africa before night."

Cyril's eyes shone.

"Then the real hunt begins," he said eagerly.


CHAPTER VII
THE RAIDERS

JUST thirty hours after leaving Marchester the crew of the "Avenger" sighted the coast of Africa. They had crossed Spain, skirted south of the Balearic Islands, and the first part of Africa they saw was the bold headland of Cape Negro, which is a little to the west of Tunis.

Far to the north-east, a mere cloud against the blue Mediterranean sky, lay the island of Sicily.

The boys had been out of their hammocks since earliest dawn, and stood together, leaning out of one of the big windows of the middle gondola, their eyes fixed upon the coast of the vast, mysterious continent, deep in the recesses of which Bertram Kent had hidden little Stella Carne.

Flying at a great height the airship drove steadily southward, and every minute the coastline grew clearer.

Tim turned a puzzled face to Cyril.

"Ye told me it was desert we was coming to. But this country—faith, 'tis green as Ould Ireland herself."

"Well, not quite that," smiled Cyril. "But you've got to remember, Tim, that we're still a long way off the Sahara. This is all old settled country with a fairly good rainfall, lots of people, and fruit groves and farms. Once we've crossed those mountains which you can see on the skyline, there'll be all the desert you want, and more too, I can tell you."

Cyril felt a touch on his arm, and, turning, saw his father.

"Still going strong, Cyril," he said. "I came to tell you that breakfast is ready. Yes; I know how keen you are to see all there is to be seen, but you'll kindly come and eat your food first."

The air at three thousand feet is a fine tonic; and the boys managed to put away an amazingly good meal in a wonderfully short time. Then they were back at their posts of observation. By this time the "Avenger" was over the land, and sweeping over orange and olive groves, big fields of grain, and flat-roofed houses startlingly white under the blaze of the morning sun.

Then the mountains climbed against the sky, and the airship cocked her nose and climbed, too. In a little more than an hour she was over them; and the boys looked down upon a tangle of barren peaks, with deep, narrow valleys between and water-courses edged with strips of brilliant green.

Another hour, and the mountains sank to hills, and beyond them lay the edge of the vast desert.

Tim drew a long breath.

"'Tis like the end of the world!" he said in Cyril's ear.

Cyril nodded. The sight awed him. As far as eye could see lay ridge upon ridge of sand-hills, dull red in colour. They were of every shape and size, and over them blew the desert wind, drifting their substance like dry snow, pulling down one dune and building up another. Far away to the left was a dark line where a caravan track cut through the dunes, but nothing was moving upon it. Not a sign of life was visible on all the vast expanse of ever-shifting sand.

"Is it all like this?" asked Tim in an awed voice.

"Not a bit of it, Tim. There's all sorts in the Sahara. There's a desert of stones beyond this, and then more sand and salt lakes and mountains, and all sorts of things."

"And how far does it go?" asked Tim.

"Well, we've come a good way, haven't we? If we went on twice as far we should still be over desert."

Tim gave a low whistle. It was the first time he had ever been out of the British Isles, and the size of the world he lived in almost frightened him.

Toward midday they had passed the sandhills which lie in an enormous crescent around the north and west of the Sahara, and, as Cyril had said, came upon the desert of stones. It looked like all the beaches in the world rolled into one, but every here and there was broken by salt-pans, which glared white as snow-fields among the endless reaches of pebbles. Passing this they came to more sand, but this flat as a floor.

"There's camels!" said Tim suddenly.

"A caravan," Cyril answered. "Look at the Arabs in their white burnouses. They're coming up out of the south, with dates or spices or saltpetre."

"And will they be crossing thim sand-hills?" asked Tim.

"They have to; but they'll take weeks where we've taken hours."

"Faith! I'd rather be up here than down there," said Tim. "Will ye look at thim dust-clouds spinning, Misther Cyril? Ye'd think they was trying to catch thim niggers."

He pointed as he spoke to two tall columns of sand which danced wildly across the great expanse.

"Watch thim. They're getting bigger!" cried Tim. "Sure that near one's as high as the big chimney at the ould Ajax Works!"

"It's a jolly sight higher than that," declared Cyril. "It's half-way up to us already, and rising every minute. Strikes me this is the starting point of a regular sand-storm."

"Thim two's joined together!" exclaimed Tim. "Ah, and there's more lifting! Will ye look at thim? 'Tis cutting off the whole country they are!"

Sure enough, the spouts were becoming more numerous every moment, and all the desert to the west was hidden by a vast dun-coloured cloud. The Arabs were off their horses, the camels were kneeling, the men had covered their heads with their blankets. Another moment, and the sand-storm swept down upon them, and hid them from sight under its gloomy pall.

The great swirl rose higher every moment. The water-ballast tanks of the dirigible were opened, and she rose too. Even so, wheeling gusts of scorching air caught and swung her dizzily. For a moment she was almost out of control, but the water continued to pour out, and presently she was out of the reach of the tempest and sailing serenely above it.

Cyril shivered.

"Those poor beggars!" he muttered. "What wouldn't they have given for a few gallons of that water we've had to chuck away!"

"'Tis a lot we've wasted," replied Tim rather gravely. "I'm thinking we'll have a job to fill thim tanks again."

Cyril nodded, but his eyes were fixed upon the gigantic cloud beneath. It now resembled a huge thunder-storm, and had taken on a deep purple colour. Its appearance was positively terrifying. Suddenly he clutched Tim's arm, and pointed.

"Look at that. It's—it's Kent's airship—and—and she's caught in the simoon!"

Hardly able to believe their eyes the two boys stared downward at the object to which Cyril had pointed. It was an airship which seemed to be of much the same shape and size as the "Avenger" herself, but floated a long way beneath her and somewhat to the east. Though half-hidden at times by the whirling summits of the vast sand-clouds, her shape was clear enough.

Tim turned to Cyril.

"'Tis an airship, sure enough, and I'm thinking it must be Kent's; but will ye tell me how it is she isn't swept away by thim whirlwinds? Sure, she's ridin' as steady as we ourselves."

"It beats me," said Cyril shaking his head. "I'll fetch Dad. He must see this."

He hurried aft, to where his father was poring over a map, and fairly dragged him to the window.

"What is it?" he demanded. "It must be Kent's ship. There can't be another so like our own."

Leaning out of the window, Mr Hamer stared hard for a moment or two at the great cigar-shaped form which seemed to swim on the surface of the huge sand-cloud. Then he drew in his head, and, to Cyril's amazement, he was smiling.

"No; it's not Kent's," he said.

"Then, for goodness' sake, what is it?" demanded Cyril.

Mr Hamer laughed outright.

"It's ours!" he said.

Cyril's jaw dropped. "Ours?" he repeated, utterly mystified.

"The double of ours, I should have said," answered his father. "In other words, a reflection of the 'Avenger' on the surface of the great cloud beneath."

Cyril drew a long breath. Tim laughed outright.

"Faith! I never was better fooled in me life. Is it what they call a mirridge, sorr?"

"A mirridge?" repeated Mr Hamer, puzzled for a moment. "Oh, a mirage, you mean! No, it's not that, but just a reflection. But you'll see mirages before you leave Sahara, Tim—plenty of them; but to see them you must be on ground-level. And that reminds me—we must refill those tanks which we have nearly emptied, and we must do it quickly too."

"Don't know what you'll fill them with unless it's sand, Dad," said Cyril.

"No; we shall find water," answered his father quietly. "There is a small oasis about two hundred miles to the south; Tamait, they call it. I propose to descend there if it seems safe."

"Natives, you mean?" suggested Cyril.

"Yes; there are wild tribes everywhere. Nearly all are thieves and robbers, but only a few, such as the Touaregs, are really dangerous."

Cyril was going to ask about the Touaregs, but at that moment Saunderson came up and called Mr Hamer away.

The "Avenger" passed on, the storm was lost in the distance, and presently a range of barren, blue mountains became visible a long way to the south-east. Cyril had a look at the map.

"The Tasili Range, they call it," he said. "Look, Tim! There's actually some greenstuff. 'Pon my word, they're real trees!"

Tim shrugged his shoulders. "I wouldn't wonder at anything now," he observed.

Two hours passed, and the airship had passed the eastern end of the hills and was crossing a rolling country seamed with deep, dry watercourses. She was coming lower, and presently a brilliantly-green patch showed up against the yellow sand.

"There's Tamait," cried Cyril. "Are we going down, Dad?"

"We are going over it just to see if all is safe. This is no country in which to take chances," answered his father.

At a height of only three hundred feet the "Avenger" sailed across the oasis. Feathery green palms surrounded a little blue lake, and were reflected in the calm water.

"Sure, 'tis the prettiest thing I iver did see," declared Tim. "'Twas worth crossing that ould desert just to get here."

As there was no sign of life in the oasis, the "Avenger" was brought to ground just outside the ring of palms, and moored by her patent anchor to a spring cable. The sand was soft; there was no wind. Presently her crew were all stretching their stiff legs on the desert.

Leaving two men on guard, the rest took aluminium buckets and went off toward the lake. The tanks had to be filled before dark, and there was not too much time.

It was hard work, and when it was finished Cyril begged his father to allow him and Tim to have a dip before supper.

Before answering Mr Hamer focused his powerful field-glasses and swept the country round. Then he nodded. "Very well," he said, "but I shall only give you half an hour. Then you must be back here."

In huge delight the two rushed off, and, flinging off their clothes, hurled themselves into the lake.

After the baking heat of the day the cool, clear water was a joy.

"Life's worth living even in this howlin' desert!" cried Tim in high delight. "'Deed, and I don't think I iver enjoyed anything so much."

The pair dived and swam and played all sorts of pranks, and, of course, forgot the time. It was Tim who first realized how late it was getting.

"Hurry, Misther Cyril," he cried. "The sun's tumbled out o' the sky, and it'll be dark in two twinks."

He was right. There is no twilight in the desert. Down goes the sun, out come the stars, and it is night before you realize it.

The pair were dressing with all speed when they heard a shout from the direction of the airship.

"Didn't I tell ye?" said Tim. "'Tis the masther calling us."

"All right; we're coming," shouted back Cyril, but the words were hardly out of his mouth before there was a strange drumming noise, which grew like a storm.

"What's that?" he asked sharply. His answer was a rattle of rifle-shots and the whine of bullets through the night.

Next moment mounted figures came racing out of the gloom, galloping furiously up out of the desert.

"It's Arabs—raiders, Tim!" gasped Cyril. "Run like fury, or we'll be cut off!"


CHAPTER VIII
IN THE HANDS OF THE ENEMY

DODGING and ducking among the tall, straight trunks of the palms, the two boys dashed away in the direction of the "Avenger," the great dark bulk of which lay all along the sand not more than three hundred yards away.

Cyril was the first to reach the edge of the oasis, where the palms stopped and gave way to open desert. He pulled up short and flung out an arm to stop Tim.

"They're between us and the ship," he muttered. "Lie down, Tim. It's our only chance."

There was no help for it. Out in the open a troop of horsemen, at least fifty in number, were wheeling. Night as it was, the air was so clear that their forms were quite visible. They were tall men, dressed in dark camel's-hair burnouses, and each had a band of black across the upper part of his face.

"Touaregs!" panted Cyril—"the masked riders of the desert. Where on earth did they come from? I say, this is serious, Tim."

"Ah, don't be worrying. Wait till they get the machine-gun on the spalpeens."

As he spoke the great white beam of the "Avenger's" searchlight darted out and fell full upon the troop of raiders. Their horses pranced and fretted in the glare, and one or two made a clean bolt. But most held their ground, and several more shots were fired.

A voice came from the "Avenger," addressing the Arabs in what appeared to be their own language.

"It's Dad," whispered Cyril. "He's telling them to clear, or he'll shoot."

Yells of defiance were the answer, and a fresh volley from the Touaregs.

"Now let them look out," muttered Tim, under his breath.

Sure enough, the "Avenger's" machine-gun began its coughing stutter, and a storm of bullets sprayed the sand. A dozen horses fell at once, and like a flash the rest wheeled and went dashing back into the palms.

"Holy smoke, but they're right on top of us!" gasped Tim.

"Lie close," hissed Cyril in his ear. "It's our only chance."

As he spoke, he wriggled in behind a palm-trunk, making himself as small as he possibly could. Tim followed his example just in time to escape the flying hoofs of one of the raiders' steeds.

The firing from the "Avenger" ceased abruptly The boys knew this was on their account.

The raiders had pulled up behind the shelter of the palms, and were firing from their cover at the dirigible.

"Will we run for it?" breathed Tim in Cyril's ear.

"No use. They'd shoot us down before we could get half-way," answered Cyril.

"If we don't, they'll nab us. That's one thing sure," said Tim.

Cyril glanced round. He realized that Tim was right. The men were all around them.

"All right. Bunk for it," he answered recklessly.

Together they leaped to their feet and ran.

Instantly there was a loud cry behind them, and two of the raiders came galloping out on their track. The boys ran as they had never run before; they ducked and twisted like eels. It was quite useless. Men like the Touaregs, who live their whole lives on horseback, and, going at full gallop, can pick a handkerchief off the ground, are not to be balked by boys, however agile.

Next moment an iron hand clutched Cyril by the arm, and he was swung up on to the crupper in front of his captor. A cry told Cyril that Tim was also a prisoner. Instantly the trained horses swung, and were in cover again like a flash.

One of the Arabs gave a hoarse order. Next moment the whole cavalcade was in motion, retreating through the palms across the oasis. They rode quietly until they reached the far side. Then, with one accord, they drove their heels into their horses' flanks and went away like the wind across the desert.

Cyril, flung across the pommel like a sack of coals, felt the dry, cool air whistle past his ears as the whole troop went flying through the night. He was desperately uncomfortable in body, but much more uncomfortable in mind. He felt that this horrible fix was entirely his own fault, and bitterly reproached himself for having been such a fool.

Thud! thud! All around him the hoofs of the galloping horses beat a tattoo on the hard sand. He tried to look round, but, though he screwed his head as far as possible, could get no glimpse of the "Avenger." He took it for granted that she would rise in pursuit, but the start would take some time, and meanwhile the Touaregs would be miles away. He was aware that they were making for the mountains to the east. No doubt the raiders had secret refuges among those great peaks, and, once they reached them, would be out of sight even of the soaring airship.

In any case there was a good eight hours' darkness before them, and during all that time the wild tribesmen would be safely hidden under the veil of night.

On they galloped—on and on. The horses seemed tireless. Cramp seized Cyril, and he groaned in agony. He began to get desperate, and to feel that, if he had any chance at all of damaging the brute who held him, he would seize it, even if it meant his own end next minute.

There was a knife in his pocket. If he could only get at it, he decided that he would stab the Touareg. But the moment he began to wriggle so as to shift his body round and get at his pocket, the Arab seemed to understand exactly what he was after.

Uttering what Cyril, though he could not understand it, felt certain was a fierce threat, the man tightened his grip on Cyril's body till the boy could have yelled with the pain.

For a time Cyril kept quiet, but even now he had not given up hope. He began to feel about with his left hand, which was more or less free, and presently his groping fingers found what he wanted. It was nothing but a common, ordinary, everyday pin, of which he always kept a few in the lapel of his coat.

Very cautiously and slowly he withdrew it, and his hand stole downward as slowly and stealthily as before. By this time the troop of Touaregs were becoming scattered, and naturally the men who were holding Cyril and Tim had fallen a little behind. Even the best of horses feels a double load.

Keeping one eye on the tall, black-bearded ruffian who held him, Cyril slipped his left hand downward over the horse's neck. He was going to hurt the horse, and he hated it. Still, it would not do the fine animal permanent harm, and his life and Tim's, beside the success of the whole adventure, hung upon his own efforts.

Waiting his chance, he suddenly drove the pin deep into the horse.

The sudden pain made the horse swerve sharply. Cyril had reckoned on its either bucking or bolting. It did neither, but must have crossed its legs, for next moment down it came, flinging its rider and Cyril right over its head.

The Arab fell heavily, and the horse rolled on him; but Cyril, who was prepared for something of the sort, managed to fling himself clear, and though the force of the fall knocked the breath out of him was not hurt.

As he sprang up he saw that the rest had swept on, and that the nearest horseman was a good forty yards ahead. The Arab was evidently damaged, for he lay still, but the horse was scrambling to its feet.

Like a flash, Cyril caught the horse by the bridle and leaped upon its back. Then, whirling it round, he was off full clip in the opposite direction. It went to his heart to abandon Tim, but he knew it was only throwing away his own life to make a single-handed attempt at rescue. Besides, he had his plan all settled, and he meant to stick to it.

The horse was unhurt, for it went off as strongly as ever. But Cyril had not covered more than a hundred yards before a savage yell burst through the night, and, glancing back over his shoulder, he saw the whole band start off in pursuit. Settling himself in the saddle, and bending low over the horse's withers, he set himself to ride.

Presently rifles cracked and bullets screamed viciously overhead. One came so close that he actually felt the wind of it upon his cheek. But it was too dark to aim, and Cyril was sure that only by chance could he be hit. The firing sent his horse on harder than ever, and, although it had probably covered many miles already, the line beast showed no signs of flagging. Cyril's weight was nothing compared with its former rider's.

He ventured to look back. The pursuit was tailing out. The nearest rider was nearly half a mile behind. There seemed to be only half a dozen left in the chase.

Now Cyril began to watch anxiously for the "Avenger's" lights. He reckoned she must already be under way, and that she would be about three or four hundred feet up, searching for the raiders. Then it occurred to him that in all probability she would be flying with lights dimmed, so as not to be seen by the enemy or give them a chance of firing at her.

In that case—but to follow out such a train of thought sent cold shivers down his spine. Even if he shook off his pursuers, he would be left helpless, without food or water in the very heart of this enormous desert.

A faint buzzing reached his ears, and quickly grew to a low drone. He knew it at once for the sound of the "Avenger's" engines.

The sound grew louder. Ah, there she was, with her long, dark shape outlined against the brilliant stars. As far as he could judge she was about five miles away, but coming in his direction.

There was a shout behind him. The Touaregs, too, had seen her, and were redoubling their efforts to catch the fugitive.

Cyril's horse was now beginning to flag a little, but those of his pursuers were still more tired. He still gained, and his spirits rose once more. Another minute or two and the airship would be right over him, for he had turned a little, and was heading straight toward her. Surely they would see him!

The roar of the six great engines grew louder and louder. She was almost overhead. Cyril shouted at the top of his voice, though, of course, he knew perfectly well they could never hear him.

She was over. She was past! Ah, suddenly the night was cut by a sword of white fire as the ray of the searchlights flashed downward.

They had seen him!

No. The light fell full upon the raiders, who turned, and, spreading out fan-wise, galloped as if fiends were at their heels. From above came a sharp rattle of firing. The "Avenger" swept on in pursuit, leaving Cyril with an almost foundered horse alone in the midst of that great desert.


CHAPTER IX
THE "AVENGER'S" RETURN

FOR the moment Cyril hardly understood his plight. Although the "Avenger" had passed, her machine-guns were still rattling, and the brutal Touaregs were at her mercy. Though they scattered, and rode this way and that, the big airship hunted them as a hawk hunts partridges. One after another they were caught by a storm of bullets and destroyed.

It was the horses that Cyril was sorry for. As for the men, he had no pity for them, for he knew them for what they were—black-hearted raiders, robbers, slave traders, not one of whom had ever done a day's honest work in his mis-spent life.

Presently one only was left, spurring his flagging horse madly in the far distance. But the white glare of the searchlight was on him, and Cyril knew that he would never live to tell the tale of how his comrades perished.

He watched till the fugitive was a mere dot in a patch of white light. Then faintly came one more volley, and he, too, toppled over and lay still.

For a minute or two the great beam still flung its searching finger over the desert sand. Then it snapped out, and only the faint light of stars lit the quiet night.

Now, at last, the full realization of his position struck Cyril like a blow, and he found himself shivering with the horror of it. But this did not last long. He shook himself angrily.

"Steady, you idiot!" he said to himself. "When they've found Tim they'll come back for you. I've only got to find the oasis again and wait there."

He slipped out of the saddle, and stood by his horse's head, stroking its soft muzzle. The poor beast was covered with sweat, and shivering a little. The desert grows quickly cold at night; and Cyril, who had nothing on but breeches, boots, and a cotton shirt, was beginning to feel very chilly. He was also very thirsty.

It occurred to him that he might find a water-bottle on one of the dead Arabs, and he led his horse gently forward to the nearest.

Man and horse were both dead. For a moment Cyril paused. There was something horrible to him in even touching the dead. But he mastered the feeling, and, stooping, took the man's water-bottle, and drank. Then he gave the horse the rest of the water. It was curious to see how perfectly the animal understood drinking out of a bottle. It put its head up and allowed him to pour the water down its throat.

Next, Cyril drew off the man's burnous and flung it over his own shoulders. It was beautifully woven of camel's hair, and kept him warm. He moved to the next body, got a second cloak, and threw it over the horse. This man had a lump of dates attached to his saddle and also a small bag of barley. Cyril fed the horse, and then himself.

After that, as there was nothing else to do, he sat on the sand with the bridle over his arm and waited.

He looked at his watch. It was only a little past twelve. Five hours still before daylight.

Half an hour dragged by. Each minute seemed like an hour. It was very cold now, and Cyril was grateful for the cloak.

Suddenly he sprang to his feet, listening intently. Yes, it was the hum of engines in the distance. The "Avenger" was returning!

The sound grew louder. A few moments later the searchlight broke out from high overhead and began to swing in wide arcs across the desert.

Shouting, Cyril ran forward, and next instant the light caught him and he stood blinking in its dazzling glare. Then the engines stopped, and the great airship settled slowly toward the sand.

"Have you got him? Have you got Tim?" was Cyril's first question as he dashed alongside.

His father came leaping out.

"You, lad?" he cried. "Thanks be that you, at least, are safe."

"But Tim," urged Cyril—"Tim. Where is he?"

"I don't know. At least, I am not sure. But my impression is that the raiders have taken refuge in another oasis, some twelve miles away. Their tracks led to it, but did not leave it."

"And you left them there? Oh, Dad, how could you?"

"We had to come back for you," returned his father, and his voice was a trifle stern. "We knew, of course, that one of you had escaped. There was nothing else that could have brought those ruffians back over their tracks."

Cyril hung his head. "It was all my fault," he said with a groan. "You told me to hurry, and I forgot."

His father laid a hand on his shoulder. "Never mind, Cyril. We all do foolish things at times, and none of us could foresee that the Touaregs would rush us in that fashion. The one thing now is to find Tim, and rescue him from these ruffians. It must be done quickly, too, for once they get away into the mountains they have caves in which they can hide, and where we may never find them again."

"I know—I know," Cyril answered quickly. "That's why I broke away. I came back to tell you, and show you which way they had gone."

"How, in the name of sense, did you get away from the scoundrels, boy?"

It was the ironmaster who spoke. He had come up without the others noticing.

"I'll tell you all about that later, Mr Carne," said Cyril. "What we have to do now is to rescue Tim."

"All very well to talk, but how are we going to do it?" growled the big man. "These fellows have hidden themselves in a clump of palms, and if we go back there and start shooting we're as likely to kill the Irish boy as any of the raiders."

"But the Arabs will have left the palms as soon as they saw the 'Avenger' move off," returned Cyril. "I'm sure of it. They'll be galloping for the hills. There's only one thing to do—chase them in the 'plane."

"Why not in the 'Avenger'?" grumbled Carne.

"She's too big, sir, and too much at the mercy of their bullets, if she comes low enough, to do any good. The 'plane is so small and so quick, they'll never hit her. Besides, she's even faster than the 'Avenger.'"

Mr Hamer cut in. "Cyril is right, Carne," he said, with sharp decision. "Get all hands to work rigging her. Mackenzie or Saunderson can take her."

"No, Dad. Let me take her," said Cyril sharply.

"You!" gasped his father. "What do you know about it?"

Mortimer Carne gave a sudden harsh laugh. "More than Saunderson, Hamer. The boy had his pilot's certificate weeks ago. So has M'Keown."

Before his father could find words to express his amazement, Cyril had darted off toward the "Avenger," and was shouting to the crew. At once all was bustle and activity. The 'plane, which had been cleverly packed in the bow gondola, was got out, the hinged wings were opened out, the tanks were filled, and within an amazingly short time she was ready for flight. Cyril scrambled into the pilot's seat.

"Have ye got all ye want?" asked Saunderson gruffly.

"Everything—cartridges, food, water—yes, it's all here. Contact!" Saunderson spun the tractor, the engine broke into crackling life, and the little machine was trundling rapidly across the hard sand.

"Can he really handle her?" asked Mr Hamer of the ironmaster, in a voice that shook a little.

"Watch him," replied the other, with a grim chuckle. And even as he spoke the 'plane lifted into the air, and, rising steadily, went off at tremendous speed into the night.

"We'd best be following," remarked Saunderson dryly; and the others hurried aboard the "Avenger."

The "Imp," as the little 'plane was called, was a tiny thing with a wing-span of only thirty feet. But she was the very latest and most perfect of her kind, magnificently engined, and fit for one hundred and twenty miles an hour in still air. She carried a special little machine-gun capable of spraying bullets at the rate of eight hundred a minute, and half a dozen tiny but very powerful bombs were in her racks.

Cyril let her out for all she was worth, and, as he did not rise high, the speed at which he passed over the ground almost frightened him. The sand-ridges whistled by like palings of a fence.

He had received exact instructions as to the position of the oasis, but as, even if he had gone high, it was too dark to get a sight of the clump of palms until right over them, he was forced to steer entirely by compass.

The distance, he knew, was about twelve miles, and he reckoned to cover it in eight minutes. But at the end of ten he could not see the clump, so, feeling sure he had missed and passed it, he wheeled and made a big circle. He had to circle twice before he spotted it, and by that time he was quivering with impatience. It had taken some time to set up the 'plane, and was now nearly three in the morning.

At last he got it, and went hurtling along low over the tops of the palms. He hoped, if by any chance the Touaregs were still there, to draw their fire. But though he almost touched the feathery fronds of the tall palms there was no response, nor the slightest sign of life about the grove.

The oasis was a very small one, and the trees not too close to see the ground below. It was not long before he became certain that the raiders had left it, and no doubt were making at best pace for the wild hills to the north.

He dipped till he nearly touched the sand, and, sure enough, there were tracks leading due north. He hesitated no longer, but went off at full-speed toward the mountains.

The next quarter of an hour was a time of intense strain, for Cyril was certain that, if he missed the troop, and if they should gain the hills, it was all up. Tim's captors would shelter in some dark cavern where neither gunfire nor bombs could reach them.

He rose to a height of seven or eight hundred feet, and now could see the mountains quite plainly, their bare, jagged peaks making a sort of fretwork-pattern against the stars. His spirits sank still lower. It seemed all odds that the Touaregs would gain those deep defiles before he could find them.

He leaned over the edge of the fuselage, and, though the rush of the air nearly blinded him, stared out across the desert.

A little dark patch, away to the east and faint in the starlight, caught his aching eyes, and he shouted aloud. The patch was moving. It was clearly a knot of horsemen.

Banking steeply he went tearing in pursuit, and in less than two minutes was above their heads.

Flashes lit the gloom, but the thunder of his big engine drowned the crackle of carbine-fire. As for the bullets, Cyril never gave them a thought. He could not return them. That he knew, for if he did Tim was as likely to be a victim as any of the raiders. Instantly he had made up his mind what to do, and, tilting the nose of the "Imp" downward, he dived straight at the company of raiders.


CHAPTER X
WHEN THE DAWN BROKE

KNOWING that he could not use either his gun or his bombs, Cyril had resolved to make his 'plane itself his means of attack.

Down he swooped, the air screaming past him. The Touaregs saw him, but had no time to scatter. A few swung in their saddles and fired.

Then he was on them, the wings of the "Imp" almost brushing their twisted turbans.

It was just as he had expected. Mad with fright, the horses bolted in every direction. Rising again, Cyril came round in such a sweep that for a moment the 'plane was almost at right-angles to the ground. As he righted her, he spotted the one horse in the troop that bore a double burden, and made for it.

Its rider saw him coming, and with all the strength of his iron wrist, wheeled his horse to one side. He overdid it. The poor beast came down, and as Cyril hurtled past, he saw the Arab and Tim rolling over and over on the ground.

Cyril turned so quickly that it was just luck and nothing else which saved him from a side-slip that would have meant a crash. Then the "Imp's" wheels touched the ground, and before he could check her speed she was almost on top of the fallen horse.

Pistol in hand, Cyril leaped out on to the sand.

"Tim!" he cried. "Tim!"

A short, square figure rose to its feet.

"Faith, I'm mighty glad to see ye, Masther Cyril," came a voice which, though weak and hoarse, was amazingly cheerful.

"The Arab—what have you done with him?" panted Cyril.

"Oh, him, is it? 'Deed then I'm afraid there's been a bit of an accident, Masther Cyril. Ye see, he tried to stick a knife in me, and I couldn't be letting him do that. So I'm thinking I've hurt him."

In spite of everything Cyril nearly laughed. The idea of Tim, five-feet-nothing in his boots, hurting the great six-foot Arab was too funny. Yet, knowing, as he did, Tim's amazing quickness and strength, it was perhaps not so funny, after all.

"Is he dead?" was what Cyril actually said.

"Sorra a bit of it! But he's a nasty hole in him, and he'll be needing a bit o' doctoring."

Cyril glanced at the Arab, who was lying quiet enough. Then he looked round quickly.

"There's no time for it, Tim," he said quickly. "The beggars are coming back. We must skip as quick as we can. There are still too many for us to tackle."

Tim nodded.

"It's right ye are. In wid ye, Masther Cyril. I'll be taking on as pilot this trip."

"Nonsense, Tim! Not after what you've been through. I can handle her. You get in behind and find yourself some grub. There's a flask of water, too, and you'd best have a dose."

"'Tis a dose of another sort we'll be having if we're not quick," returned Tim grimly. "In wid ye."

As he spoke he ran toward the 'plane, which lay no more than twenty or thirty yards away.

Before he reached it the darkness was lit by a dozen bright flashes, and the crackle of carbine-fire rattled through the night. There was a sharp clang as a bullet hit some metal part of the "Imp."

"What did I tell ye?" said Tim, as he flung himself into the pilot's seat. "The villains are on us. Now, don't be arguing. Give her a swing, and let's be moving."

Tim was right, and Cyril leapt to the propeller. "Are you ready?" he cried.

"I am not," came Tim's answer. "Here's throuble for us. One of them bullets has hit the petrol-tank. We'll not be able to shift till I get the hole stopped."

Cyril gasped in dismay, but before he could answer a fresh volley burst out and bullets hummed like wasps all around them.

Cyril sprang back to the side of the 'plane.

"We must fight them off. The machine-gun—that's our only chance. I'll handle it out here while you see what you can do with the tank. There's spare petrol in the tins."

"Here you are, then," said Tim, curtly, as he handed the machine-gun over the side.

To detach the gun from its special mounting in the 'plane was a second's work. It could then be used on an ordinary tripod on the ground, from which position an almost uninterrupted sweep of the surrounding desert could be obtained.

Cyril squatted down behind the gun. A belt of cartridges was ready. Next moment a stream of flame leaped from the muzzle, and a continuous crackle of firing sent echoes pealing out across the desert. Cyril could not see the Touaregs, but he knew their direction by the flashes from their carbines, and, swinging his gun back and forth, he hosed them with lead.

"That's stopped 'em," remarked Tim. He had fixed a little electric light over the seat of the damage, got out a case of tools, and was desperately busy trying to tinker up the holes made by the bullet.

"For the minute," replied Cyril. "How many do you think there are, Tim?"

"All of thirty," said Tim. "And sons of sin, ivery soul of thim."

"I wonder what they'll do next."

"Circle round, like Injins, and take pot-shots," Tim answered. "That's what I'm thinking."

He went on with his work, and Cyril sat silent, straining his eyes through the gloom in a desperate effort to find out what was happening. He could not hide from himself that the state of things was well-nigh desperate. If it had been daylight it would have been different, but the darkness was all on the side of the enemy, who, as Tim had said, could scatter and make rings round the 'plane.

They could see the 'plane, but he himself could not see them, and he could not afford to keep blazing away into the darkness. Cartridges are heavy things, and he only had three belts in all.

Crack! Crack! Just two shots, but they came from exactly the opposite direction from the first volleys. Crack! Crack! Two more from the east.

"You were right, Tim," said Cyril. "They're surrounding us."

"They're mighty poor shots," replied Tim, with some contempt. The words were hardly out of his mouth before another volley of three or four shots together rang out, the electric lamp in Tim's hand went to flinders, and Tim himself gave a sharp cry of pain.

"Oh, Tim! Are you hurt?" cried Cyril, in dreadful anxiety.

"Not me! 'Twas the torch!" growled Tim, wringing his hand. "Arrah, but I've pins and needles up to my shoulder. Shoot back at thim a bit. They're coming a deal too close."

Cyril's finger was already on the trigger of the machine-gun, and a score or so of bullets whipped the desert in a wide half-circle. This gained the boys a little peace, and Tim, getting a fresh torch, went on with his work.

"Where's the airship?" asked Tim. "Isn't the 'Avenger' coming along?"

"They were starting when I left," Cyril told him. "But whether they'll find us is another matter."

Time passed, and there was no more shooting. But Cyril took little comfort from this. He thought it was most likely that they were crawling up through the gloom, making ready for a rush from all sides at once.

It was getting toward dawn, and, as is always the case, it was the darkest time of the whole night. The silence was broken only by the steady tap of Tim's hammer.

"How much longer will you be, Tim?" asked Cyril in a low voice.

"Half an hour yit. Ye see, it's not as if I could be brazing it."

"Can I help?"

"Sure, the best help ye can give is wid the gun. I'm misthrusting thim black-faced beggars will be rushing us before long."

"That's my notion, too. If only the airship would come! I thought I heard her engines just now, but couldn't be sure."

"Don't be worrying," said Tim. "Sure, it'll be light before a great while. Thin we can snap our fingers at an army of thim."

Cyril said nothing. He was listening till his ears ached.

Time dragged by, and still no sign of the enemy. Tim had finished the mending of the hole on one side of the tank and was busy on the other. And now the darkness was beginning to lift a little, and that curious pale-lemon tint which comes before dawn on the desert was dimming the stars.

Cyril's heart beat painfully. Had the Touaregs really given up and gone? It seemed like it. Anyhow, the next quarter of an hour would show. They must attack or lose their chance with the approach of daylight.

The stars paled, and in the east a faint pink stained the sky. Cyril, looking round, was able to see the outlines of the hills to the north. Their lower spurs were much nearer than he had imagined.

"I'm nearly finished," announced Tim. "Another ten minutes and I'll be ready for the petrol."

Still Cyril did not answer. He was certain he could hear something, but it was not the "Avenger's" engines; it sounded more like the thud of the feet of many horses.

The light was getting stronger every minute, and he could see that the foot of the hills was less than a mile away, and that almost opposite the spot where the "Imp" lay upon the sand a narrow pass, or defile, opened out upon the plain.

He drew a long breath.

"Here they come, Tim," he said quietly. As he spoke he pointed to the mouth of the pass, out of which was pouring the head of a column of wild horsemen.

Tim jumped down to Cyril's side. He gave a low whistle. "'Tis an army—no less!" he muttered.

An army it was. There were hundreds of them. Now at last Cyril understood the reason why he and Tim had been left in peace for so long. Their attackers had ridden back into the hills for reinforcements, and here was the whole tribe gathered for battle.

His eyes brightened, and his jaw set.

"They've asked for it," he said. "They shall get it."

As he spoke he swung the muzzle of the machine-gun round so that it bore full on the head of the advancing raiders.

Out they came—score after score. "Hundreds of them!" as Tim muttered uneasily. They spread out fan-wise and came galloping madly across the desert, the dry sand rising in clouds under their flying hoofs.

Head down, eyes sighting along the barrel, finger on the trigger of the machine-gun, Cyril waited in silence.


CHAPTER XI
THE LAST CHARGE

CYRIL waited till the Arabs were within two hundred yards. Then, as coolly as an old soldier, his finger pressed the trigger, and the machine-gun's snapping crackle woke the echoes.

The raiders had already learnt enough of the gun's deadly powers to respect it, and had opened out into a wide semicircle. Even so, the storm of bullets did terrible execution. A score or more of men and horses went rolling on the sand.

The rest stopped.

"That's sickened 'em," said Tim in Cyril's ear. "Give 'em another dose, and 'twill turn 'em."

"I've only one more belt of cartridges," Cyril answered. "I must keep it. They're bound to rush again."

"Only one more belt, is it?" Tim's grin faded. "That's bad," he whispered.

"Ah, they're starting to shoot again. Kape down."

The Arabs had changed their tactics. They were galloping up and down, firing as they went. Bullets whistled past like bees. The 'plane was hit a dozen times, and it was a miracle that neither of the boys was touched.

Cyril made no move, but kept a watchful eye on the enemy. He was not feeling happy. If the Touaregs charged again the end was certain. He might finish another score, but there were so many of them that this would make little difference. They would swamp the defence by sheer weight of numbers, and then the end was certain.

Tim spoke again.

"Be ready. I'm thinking the big rush is coming this time."

Cyril nodded. He, too, had noticed certain signs being made by men who were evidently leaders of the wild tribe. Meantime the firing went on, and he and Tim were forced to crouch low behind what small shelter the body of the little 'plane provided.

Suddenly the firing ceased.

"Now for it!" murmured Tim.

Sure enough, next instant almost the whole of the raiders swung inward and charged. It was a terrifying sight—some three hundred of the wild horsemen, with their fierce eyes, high cheekbones and beak-like noses, galloping furiously down upon the two boys. Inwardly Cyril felt certain that this was the end, and that all he could do was to take as big a toll as possible of the enemy before dying.

At that moment his thoughts flashed back to little Stella Earle, still prisoner in the hands of the brutal Kent, and he longed to be able to tell his father not to give up the search.

Again his finger was on the knob of the machine-gun trigger, but he did not press it. He meant to wait till the last moment before loosing off his remaining belt of cartridges.

The raiders came down upon the 'plane at full speed. They were not shouting now, and the only sound that broke the quiet of the desert dawn was the drum of hundreds of horses' hoofs upon the hard sand.

Cyril waited until he could see the whites of the eyes of the leaders. Then at last he let loose.

It was a massacre. At such a range almost every shot told. Of the first score not a man or a horse escaped, and those behind crashed into the fallen and fell over them, until a barrier of men and horses was piled high at a distance of no more than fifty yards from the 'plane.

"Stopped 'em again!" roared Tim, but Cyril did not share his triumph. If he had had the cartridges, now was the time to use them. But there were at most three dozen left, and once they were gone it was the end. He must keep these few for the last moment.

The Touaregs realized quickly enough that Cyril had ceased firing. One of the leaders shouted a hoarse order, the rest rallied and came on once again.

Once more the machine-gun clattered fiercely, but it was only for a few seconds. Then she was silent—and for good.

"That's the last," said Cyril.

"Last! Not be a long chalk!" retorted Tim, and, leaping to his feet, flung something small and round straight at the nearest Arab. With a crash of sound the bomb exploded, and man and horse simply vanished off the face of the desert.

"Hurrah!" cried Cyril recklessly, and, snatching an armful of bombs from the 'plane, he and Tim together charged the Arabs, pelting them with the terrible little missiles.

Badly shaken already, the raiders turned and bolted, leaving the ground piled with dead.

"Faith, I knew they'd niver stand thim things," cried Tim.

As he spoke rifle-shots crackled, and bullets sent puffs of dust spouting all around the two boys.

Cyril seized Tim by the arm.

"Back to the 'plane!" he said sharply. "They've not done with us yet."

Tim's jaw dropped.

"And we've used the last o' thim bombs," he answered dully.

There was not a single cartridge or bomb left. The boys were quite defenceless.

Nor was it long before the Touaregs understood the state of things, and once more they mustered their forces.

Reaching the 'plane, Cyril replaced the gun in the body of the machine and then turned to Tim with outstretched hand.

"Good-bye, old chap," he said.

Tim looked Cyril full in the eyes.

"No," he said, "no, Masther Cyril. I'll not believe it till we're down and out. Sure we'd niver have come through last night if we were to be scuppered like this in the morning."

Cyril smiled.

"My dear Tim," he answered, "nothing can save us but a miracle. It's only a question whether the Arabs will smother us by a fresh charge, or sit tight and pick us off from a distance.

"Anyway," continued Cyril, "they must soon guess that we have run out of ammunition, and then it is likely to be all up with us."

Tim looked toward the raiders.

"They're gathering again," he said; and taking his clasp-knife from its sheath at his belt, opened it and felt the edge.

"Anyways, we'll finish a few more before we're through wid thim, and maybe the 'Avenger' will come along before they're done wid us entirely."

Cyril glanced round.

"She'll have to be pretty quick," he said. "Ah, here they come!"

The raiders had made up their minds to try a fresh charge. The chief had given the signal, and a large body was forming up with extraordinary quickness.

"If we only had one more belt of cartridges!" groaned Cyril.

He was thinking of what Tim had said, and feeling that it really was too hard to be wiped out like this, after going through such a night and coming out safely from so many dangers.

The Arab chief, a huge man with a gaunt, fierce-looking face, shouted an order. Before it could be obeyed the cool dawn air was pierced by a thin whistling sound which grew with extraordinary swiftness to a shrill hiss.

Next instant something struck the ground right in the centre of the Arab squadron. There was an appalling crash, and up burst a vast cloud of flame and smoke mixed with other things which were not dust or smoke.

Though the boys were fully two hundred yards from the scene of the explosion, the blast of air flung them down.

Tim was up again, quick as the bounce of a rubber ball.

"I tould ye so!" he yelled. "Didn't I tell ye, now? Look, will ye. Look up!"

Cyril looked up. So high overhead that she seemed no larger than a pencil against the blue, hovered the long, slim form of the "Avenger."

Even as they watched her she grew in size as she dropped swiftly downward out of the sky.

"She came over widout her engines," went on Tim breathlessly. "That's why we didn't hear her."

"No more did the Arabs," remarked Cyril, as he stared out across the plain toward the great crater made by the explosion.

"They're done this time, anyway," cried Tim in triumph. "Will ye look at thim run?"

Sure enough, the Touaregs were running, or, rather, riding. The bloodthirsty brutes had at last had enough, and were galloping madly for the mouth of the rift.

"Sure, I wish the masther would give thim another," declared Tim, as he watched the frantic rush for safety; but Cyril shook his head.

"We've Kent to reckon with yet, Tim. I expect we shall need every bomb we've got before we've finished with him. But here's the 'Avenger.' Let's go and tell them how jolly grateful we are to them for getting us out of this mess."

"This Arab you wounded, Tim, where is he?"

Mr Hamer asked the question. They had already been round the battlefield, and given first-aid to those who were not beyond it. There were very few of the Touaregs left alive. The bomb had finished most of those who had been merely wounded.

Tim looked round.

"'Deed, then, he's not where I left him," he answered, walking back toward the spot.

"Be careful, Tim!" cried Cyril.

The words were hardly out of his mouth before a fierce-eyed, blood-stained figure rose out of a little hollow in the sand, and a knife-blade flashed.

Cyril and his father both rushed for the spot, but it was Tim who saved himself. With a kick which was as quick as a blow from a cat's paw he knocked the Arab's arm up, and the knife flew away harmlessly.

The man dropped back, snarling like an angry dog.

"What's the matter wid ye?" demanded Tim, standing over him. "What's the grudge ye've got agin me that ye thry to let the daylight through me this second time?"

The man was silent, but he glared up at the white men with all the savagery of a trapped beast. It was quite plain to them that he expected nothing but instant death.

"Hould him while I put a bandage on him," said Tim coolly, producing his first-aid case.

The Touareg's surprise was almost comic when he found that the strangers, instead of knocking him on the head, were bandaging his wounds. But it was nothing to his amazement when they gave him water and food.

He drank greedily and ate a little. At last he spoke.

"What does he say, Dad?" asked Cyril eagerly of his father, who knew the language.

Mr Hamer turned and spoke.

"This is luck, Cyril. The man wants to know if we mean to take him to the Mountain of Death."

"The Mountain of Death," echoed Cyril. "What on earth does he mean?"

"I have asked him. He says it is the home of the Flying Ship. If I am not greatly mistaken, the place is in the oasis of Azek, and he has already seen Kent's airship travelling to, and perhaps from, that place. I think he may be able to give us valuable information."

"Good for ould Blackbeard!" put in Tim. "'Deed, and if he'll tell where that spalpeen Kent has gone it's freely I'll forgive him for thrying to punch holes in me."


CHAPTER XII
THE MOUNTAIN OF DEATH

"TEN days' ride, this man Houssein says," explained Mr Hamer, who was the only one of the party able to talk to the Touareg. "In that direction—south-west. We have come too far east, apparently."

"How much is ten days' ride?" asked Cyril.

"Between three and four hundred miles. Where is the chart? Ah,"—as Cyril opened it—"here we are! It must be beyond 20 north latitude, somewhere in the centre of this blank space."

"Then it isn't El Azek?" put in Cyril quickly.

"No. El Azek is farther east. Still, it is likely that Kent would get his supplies from the oasis of El Azek, and it is quite probable that he despatched his blackmailing letter from that point. There is a caravan route from there."

Cyril looked a little doubtful.

"Are you quite sure that this fellow isn't pitching us a yarn?" he suggested.

"He has no reason to do so. And I am convinced that he had seen an airship before he set eyes on the 'Avenger.' If so, it can be no other than Kent's. He says that his tribe and all the people of these mountains have been watching her for months past, and longing for an opportunity of capturing and raiding her."

"Then for why didn't they go to this Mountain of Death he talks about?" asked Tim shrewdly.

"Because they are scared of it, Tim. This man himself is almost afraid to mention it. I have asked him why, but he only shakes his head, and talks about Eblis and Afreets."

"And who will they be whin they're at home?" inquired Tim.

Mr Hamer laughed.

"'The devil and all his angels,'" he quoted. "Eblis is the Mohammedan devil, a snake-like monster, and Afreets are evil spirits."

"Sure, I'd a lot rather have thim to dale with than rale snakes," said Tim, with a slight shiver. Like most Irishmen, he had a horror of snakes. Mortimer Carne broke in.

"If you are convinced that the Arab's story is true, Hamer, that is good enough for me, and the sooner we push on the better. We don't want Kent to get news of us."

"I quite agree with you. Surprise counts for a good deal in a case like this. I suggest that we pay a visit, first of all, to this so-called Mountain of Death. If we find no trace of Kent there, a few hours will take us to El Azek."

"What about Houssein?" asked Cyril. "Do we take him?"

"The Arab? No," answered his father. "We'll leave him a little food and water, and he'll do well enough. His own folk will look after him. I don't suppose they are far off."

So it was arranged, and in a very short time the "Avenger" rose again, and with her great engines roaring and her huge propellers spinning, moved swiftly away in a south-westerly direction.

Cyril and Tim stood together, leaning out of a window of the central gondola. Tim yawned.

"Sure, I'm sleepy as an ould owl."

"Small wonder after last night. I vote for a spell in our hammocks."

Tim nodded, and, climbing out of the gondola on to the 'cat-walk' leading aft, the two scrambled into their hammocks, which were slung in the rigging just inside the envelope of the dirigible, and slept there, swaying over five thousand feet of thin air, as peacefully as if in their beds at home.

"Supper's ready, an' the mountain's in sight!"

It was Tim's voice which roused Cyril from dreamless sleep. He sat up, seized the stay overhead, and swung down to the narrow 'cat-walk.'

"The Mountain of Death—where is it?"

Tim pointed to a blue hump, dim on the southern horizon. Cyril glanced at it, then looked down at the country directly below.

"My goodness, what have we struck?" he gasped. "It's just as if a giant blast-furnace had been emptied and left to cool."

No wonder Cyril was surprised. They had passed over some pretty awful country already, but nothing to hold a candle to what was now beneath them. It was one appalling jumble of splintered, sharp-edged rocks, all dark in colour, and most of them as black as coal. Some were as big as houses, others mere rubble. Some were piled up a hundred feet or more in height; in other places they lay almost flat.

Every here and there the ground was split into vast seams, or crevasses, so deep and dark that the light of the westering sun could not reach the bottom. Much of the broken rock shone like black glass, the sun's rays blazing off it in the most extraordinary fashion.

"'Tis the world's ash-heap," remarked Tim. "But, as I tould ye, supper's waiting, and Misther Hamer says we'd betther ate while we have the time."

In the gondola Mr Hamer and the ironmaster were already seated, and Mackenzie and Carter with them. Vane and Saunderson were attending to the engines and steering while the rest had their meal.

"What on earth have we struck, Dad?" was Cyril's first question.

"It's the scene of an old fissure eruption, my son," answered his father. "It reminds me of the great lava desert of Oregon, only this looks more recent because there is no rain or frost here to weather the rocks. Those black shining crags are obsidian, which is practically black glass."

"An' what's a fissure eruption, sorr?" asked Tim. "Is it any relation to a volcano?"

"A very near one, only on a much bigger scale. Instead of a crater, a rift many miles long has opened under the pressure of the subterranean fires, and flung out gigantic volumes of lava. The thing that puzzles me is that this is so far from the sea."

"Perhaps there was a big lake here at one time," suggested Cyril. "We're not so very far north of Lake Tchad."

Mr Hamer nodded. "Probably there was. Indeed, there must have been, for eruptions of this kind are always caused by steam. But get on with your food, boys. We shall reach this queer mountain in little more than an hour."

As they ate they noticed that it was getting quite chilly.

"Are we rising, Dad?" asked Cyril.

"We are. I have given orders to go to the ceiling. It's our only chance of avoiding observation, and not a very good one at that. Still, the sun will be down soon, and my idea is to use the last of the daylight to get a look at this mountain."

By the time supper was finished it was so cold that every one was reaching for his warm overcoat. All day long they had been travelling at about three thousand feet, where the air was well on the warm side. This was like plunging out of summer into winter.

Cyril had his coat on first. He went up at once to the observation post on top of the car. Next moment he had swung back.

"Something in sight!" he cried breathlessly. "Get some glasses. I believe it's Kent's airship."

The rate at which they all got out on to the platform was astonishing. Even Carne, who from the first had flatly refused to move out of the gondola, because, he said, if he did he would be certain to fall, came hurrying with the rest.

The "Avenger" was now a good fifteen thousand feet up, and the air had a thin, biting cold like that of a mountain-top.

"Where—where did you see this?" demanded Mr Hamer.

"There," said Cyril, who was focusing a pair of field-glasses. He pointed as he spoke in the direction of the mountain, which was now no more than twenty-five miles away. "I have her! I see her! I was right! She's the 'Avenger's' double, only a bit smaller. Can you see her, Dad?"

"I see her," answered his father gravely. "Let us only hope they have not seen us."

"I don't see why they should," Cyril answered. "It's not likely they are keeping much of a watch. Anyhow, we are above the clouds."

"There's that, of course," said his father, glancing at the faint trails of cirro-cumulus cloud which sometimes appears over the desert late in the evening. "Yes, unless Kent is keeping a very close watch, it is not probable they have seen us. I wonder where she is bound."

"Straight for the mountain," Cyril replied "Houssein was right, after all."

No one spoke a word as they watched the long, slim object which, at this distance, appeared hardly larger than a knitting-needle, nearing the blunt summit of the Mountain of Death.

She made straight for it. Then the watchers gasped with surprise as they saw her drive apparently right upon the sloping side—and vanish!

They waited, but no, there was no sign of her reappearance. She had disappeared as completely as a needle driven into a pin-cushion.

"Uncanny sort of performance," growled Carne in his harsh voice.

"Ah'm thinking it'll be an optical illusion," remarked Mackenzie, the Scottish mechanic.

"Not a bit of it," said Mr Hamer. "It's a cave, or, more likely, a rift in the mountain-side where Kent is housing his ship. In any case, we shall know before long."

"Mackenzie," he continued, "keep at this height and half-speed. And, Carter, steer a little easterly. The wind sets from that quarter. What I want is to drift over the mountain with silenced engines, and just at dusk. Then we shall see without being seen."

His directions were carried out, and meantime, in spite of the bitter cold which made their fingers blue and their feet numb, the boys remained on the platform, watching with breathless interest.

"We've got the fellow at last, Tim," said Cyril.

"Found where he lives, ye'd betther say," replied Tim shrewdly.

"What—you mean you think there'll be trouble in getting him to hand over Stella?"

"If ye ask me that, I'm thinking we're only at the beginning of the business."

"Why do you say that?"

Tim shrugged his shoulders. "Sure, it's plain as the nose on me face. How will we be getting at him if he's got his ould airship in a cave? Wouldn't he be waitin' for us wid guns and bombs?"

"Yes," allowed Cyril, "if he has a cave. But it would take a pretty big cave to house an airship, and I think it's a deal more likely that he's got her in a rift or valley of some sort. Then we can deal with her easily enough."

"An' if we did, would that give us Miss Stella? It's Miss Stella Kent'll be hiding in a cave, and we may blow his ould airship into smithereens widout getting any forrader."

Cyril began to look uncomfortable. "I hadn't thought of it that way. You may be right, Tim, but surely he'll rather give her up than lose his airship?"

"From all I've heard of him, 'tis the last thing he'll do." Tim spoke with unusual gravity. "The man hates ould Carne like cowld poison. It's my belafe he'd sooner cut the nose off his face than give up the girl."

Cyril's lips tightened. "Then we'll take her—that's all there is about it," he answered grimly.

"'Tis that we will do," Tim answered. "But wait now. In a minute we'll be seeing where Kent kapes his craft."

The "Avenger" was now drifting slowly over the summit of the monstrous mass of rock which Houssein had named the Mountain of Death. Bare and bleak, it rose in great slopes and cliffs out of the hideous lava desert which surrounded it. Though not of any great height—perhaps not more than five thousand feet—it was evidently of vast extent, covering an area a score or more of miles long by, perhaps, twelve in width.

In fact, it was more like a great tableland than a mountain. Cyril found himself wondering how any human being could possibly live upon such a place for even a week.

"Desolate is no word for it," he said. "It looks like a great clinker lifted out of a stove."

A couple of minutes later the "Avenger" passed over the rim of the mountain, and Cyril started, and stared as though he could not believe his eyes. The scene that lay beneath him was more different from what he had expected than anything he could have pictured in his wildest dreams.


CHAPTER XIII
THE SILENT WOOD

THE mountain was hollow. Instead of a vast stretch of barren rock, which Cyril and all of them had expected, the mountaintop was scooped out like a gigantic Stilton cheese. Bare at their summits, but heavily wooded below, gentle slopes ran down to a central basin filled with water. The "Avenger's" crew looked down, from the airy heights at which they floated, upon a great lake. The sun was now so low that its slanting rays did not reach the surface, which lay like a vast mirror of polished steel, stretching for miles toward the west.

Mr Hamer stared as if he could hardly believe his eyes.

"The last thing I expected!" he said at last.

"This ould desert is full of surprises," remarked Tim; but no one paid the least attention. They were too deeply engaged in gazing downward. From the tremendous height at which the "Avenger" floated, everything below was reduced to toy-like dimensions, yet, even so, it was clear that the lake was a very large stretch of water, and that the forest surrounding it was a regular jungle.

"This complicates matters," said Mr Hamer gravely. "If we have to search this great basin it may take us weeks—months even."

"I don't care if it takes years," growled the ironmaster in his throat. "We'll find Stella."

"There's the rift!" said Cyril suddenly. "That's the way by which Kent's airship entered."

"More betoken, there she is this minute," added Tim. "D'ye see her—there in the little bay—lying on a raft on the wather?"

Sure enough, Tim's sharp eyes had picked out Kent's airship lying on a raft, or platform, in a small bay on the far side of the lake. At this distance she looked about the size of a lead pencil, and, half-hidden as she was by the great trees overhanging the lake, she was very difficult to distinguish at all.

"There she is—at our mercy—just as I told you," said Cyril triumphantly.

He turned eagerly to his father.

"Let's drop and bomb her."

Mr Hamer shook his head.

"Madness, Cyril! We must wait for night before we try anything of that sort."

"But then there will be no one there. They will all have gone to their tents or cave, or wherever they live."

"That is quite likely," allowed his father; "but, all the same, I don't think we should do any good by bombing Kent's airship. It would only make him desperate."

"It's not to be thought of," put in Stella's uncle sharply. "The brute might revenge himself on Stella."

"I hadn't thought of that," said Cyril, rather crestfallen. "Well, what are we to do?"

"Get away as quickly as possible before they see us," replied his father.

"Mackenzie! Start the aft engine with the silencer," he ordered.

"Aye, aye, sir," answered Mackenzie, and went off at once. A few moments later the engine opened up, but instead of its usual rattling roar, only a muffled thudding was heard. Mr Hamer himself took the tiller, and the "Avenger" turning northward, drew steadily away.

Mr Hamer kept her going until the lake and the whole interior of the hollow mountain had faded from sight. Then he turned westward, and they went sliding down in a long, steady slant.

"What are you making for, Dad?" asked Cyril.

"The western end of the mountain. A lake like this must have some outlet, and since it is not at the eastern end it stands to reason it must be at the west. Ah," he continued, "I thought as much!"

Thin as a thread and dim in the fast-gathering twilight, a silver streak became visible meandering across the desert, edged on either side with a broad belt of green. As the "Avenger" came nearer, this resolved itself into a river, which broke out through a deep canyon at the western end of the mountain.

"Fresh water, and trees to hide us," said Mr Hamer, with a sigh of relief. "Now, at any rate, we have a starting-point."

Presently the "Avenger" was hovering just over the forest. Mr Hamer picked an open glade, and into this she dropped, alighting as softly as a feather on thick grass.

"There, she's all snug!" observed Cyril, as the last mooring-rope was made fast.

Tim, with his sleeves rolled up over his sturdy elbows, straightened his back and wiped the perspiration from his streaming face. He looked up doubtfully at the sky, now strewn with stars.

"But supposing ould Kent takes a fly over us, what's to prevent him wipin' us all out?"

"Camouflage!" Cyril answered promptly. "First thing in the morning we are going to cover her up with that green cloth we brought along. That and a few branches, and we'll be absolutely invisible from above."

"All I hope is that Kent hasn't got wind of our arrival," growled Carne, who was standing close by. "A risky business, I call it, crossing the mountain like that."

"It's a thousand to one against their having noticed us," said Mr Hamer. "But come into the car, where we can talk things over."

The whole party gathered in the central car to make up their minds what was best to do. Mr Hamer's notion was a night attack on Kent's airship.

"Smash his airship, and he's bound to come to terms," he said.

Mr Carne was against it.

"The fellow has had time to make provision against that sort of thing," he declared. "He'll have some way out, and before he goes will hand Stella over to these abominable savages he talks of in his letter."

"What is your plan, then?" asked Mr Hamer.

"We must first find out where Kent's stronghold lies," answered the ironmaster.

"Easier said than done," answered Mr Hamer drily.

"Couldn't we work up through that rift?" suggested Cyril. "From the top we could watch and see what's happening below."

"That's the thrick, sorr," put in Tim eagerly. "Let Masther Cyril and me go and scout."

Mr Carne nodded.

"A good idea," he said. "You two boys can do better than men on work like this."

Mr Hamer did not like it—that was plain. But in the end he agreed, and it was decided that a start should be made the very next day.

Cyril went off to his hammock fairly tingling with excitement. This was going to be the biggest adventure of all, and if only Kent was still ignorant of the coming of the "Avenger," Cyril felt that he and Tim had a good chance of success.

Cyril had just got into his pyjamas when he heard a whispering near by. He slipped outside. Mackenzie and Carter were standing on the grass, gazing in the direction of the mountain.

"I tell ye 'tis a searchlight!" he heard Mackenzie say. "Have I not seen hundreds in the war?"

Cyril looked. Faint and far in the distance, to the eastward, a pencil of pale light moved to and fro across the star-strewn sky.

Carter stirred uneasily.

"Aye," he replied; "it's a searchlight right enough. Then that son o' sin is watching for us, Mac."

"He is that," replied Mackenzie. "But say nothing. It's nae manner of use to be troubling the old man's mind."

Cyril crept quietly back to his hammock. A good deal of his confidence had disappeared.

Tim paused on a rocky ledge. He was breathing hard.

"I'd niver have thought this ould mountain was half the size," he remarked.

Cyril looked ruefully up at the long and steep ascent which still rose in front of them.

"No more would I," he agreed. "Tim, my throat's like a limekiln. I must have a go at my water-bottle before I take another step."

"Just a wet, then," said Tim warningly. "It's not a lot of water we've got left, and maybe we won't find a spring so aisy, even when we are over the lip o' the rift up there."

Cyril uncorked his felt-covered bottle and took one mouthful of its lukewarm contents; then the two toiled onward. This was the second day since leaving the "Avenger," and Cyril and Tim had now been climbing for more than three hours, but the top of the mountain was still a long way off.

At last, aching, blistered, and footsore, they reached the raw summit of the pass, and looked down through the wide rift into the depths of the immense hollow.

Cyril drew a long breath.

"It's like fairyland," he said.

"Wid some mighty funny fairies in it!" retorted Tim. "Be getting on, if ye plaze. It's a sight too plain we are perched up here against the sky."

The advice was good, and they hurried on down a steep bush-covered slope until they reached the taller timber below. Here Cyril flung himself down in the shade of a thick, shrubby tree.

Tim did the same.

"Sure, we've earned a bit of a rest," he said. "And now what will we do?"

"Find a place to camp," replied Cyril promptly. "We must have a good sleep first; then in the morning we shall be fit for real scouting."

Tim nodded.

"'Deed, but you're right. It's meself couldn't tackle a rabbit to-night, let alone a grown man."

Dusk was falling as they went forward again. There was not a breath of wind, and the great wood around them was deathly still. There seemed to be no life in it, and a dry twig, cracking underfoot, sounded as loud as a pistol-shot. Now that they were among the trees, they could see nothing of the lake. It was all one tremendous tangle of green leaves and creepers.

It grew thicker and thicker. Cyril stopped.

"This is no good to us, Tim. We'd better go back and camp on the edge of the wood."

Tim merely nodded, and they turned.

Presently Tim pulled up.

"Did ye hear anything?" he whispered uneasily.

"No," answered Cyril, almost crossly. "I only wish I could."

"But I did," answered the Irish boy. "I'm thinking we're followed."

"Nonsense! Who'd follow us?"

Tim caught him by the arm and drew him down behind a huge creeper-clad trunk.

"Whist, now!" he muttered.

They lay, hardly breathing, straining their ears.

Kipling's lines came back to Cyril:

Where the silence 'ung that 'eavy you was 'arf afraid to speak.

A minute passed—another. Still there was no sound.

Suddenly Tim gripped Cyril's arm so hard that it hurt. With the other hand he pointed.

There was a bush opposite, a low bush with large, dull-green, leathery leaves.

Over the top of it a head was visible. How it came there Cyril could not tell, for there had not been the slightest sound that he could hear.

It was the head of a black man, with a face so appallingly, repulsively hideous that the sight of it made Cyril's blood run cold.


CHAPTER XIV
THE PIT TRAP

THOUGH black as ink, the face was not in the least like that of the ordinary African negro, with flat nose and blubber lips. This man's nose was almost as well-shaped as an Arab's, his forehead fairly high, and his lips rather thin than thick.

It was the hideous air of cunning and cruelty marked on every feature that made the face so repulsive. The eyes, set deep in their sockets, gleamed in the faint light like those of some dangerous wild beast, while the upper lip, drawn back and twitching slightly, showed two rows of teeth filed to points as sharp as the fangs of an alligator.

Cyril lay still as a mouse. His eyes were fixed on the horror, and he hardly breathed.

Some seconds passed; then the head drew down and vanished behind the long, leathery leaves as silently as it had appeared.

Still Cyril did not stir, and he and Tim cowered side by side, without moving or speaking, straining their ears for some sound.

There was none. Not the slightest rustle broke the utter stillness of the forest.

At last Cyril turned to Tim.

"Did we dream it?" he asked in a breathless whisper.

"We cudn't," was the answer. "'Tis not in the mind of either wan of us to picture up a face like that. Me blood's still cowld in me veins from seeing it!"

Cyril shivered.

"It was ghastly!" he answered in the same low tone. "Tim, are those the savages to whom Kent is going to hand Stella?"

"I'd think shame to lave a dog to the mercies of a thing like that," Tim answered gravely. "Did he see us, think you?"

"Just what I was wondering. I hope he didn't."

"Maybe he's watching us this minnit. I tell ye, Masther Cyril, 'tis not healthy here, where him and his fellows may be crawling around us. Let's be getting out o' the wood on to ground where we can kape a watch over ourselves."

"The sooner the better," agreed Cyril. "We must be quick, too. It's getting darker every minute. Keep your rifle ready," he whispered, as he rose quietly to his feet. "You watch out in front; I'll have an eye behind, and don't make a sound if you can help it."

Tim nodded, and they started back up the slope. Presently Tim stopped.

"I'm off the thrack," he muttered. "'Tis too dark to see the way we came."

"Keep on up the hill," said Cyril. "We're bound to get out of the wood sooner or later."

Again they went on. It was a slow business. Between the huge trunks which towered upward into the night the undergrowth grew thick as an English hedge. Great vines and creepers hung from tree to tree. Often the growth was too matted to pass, and they had to go back in order to find a way round.

A minute later they pulled up short. Right in front a twig had cracked with a report that in this utter silence, sounded loud as a pistol-shot.

"The nigger!" hissed Tim.

"It may be a wild animal," whispered back Cyril.

"Wild bastes move soft. Kape your gun ready."

They waited a little. In the silence Cyril could hear his own heart beating. All was quiet, and after a bit, he spoke in Tim's ear.

"We'll go round a bit—this way."

He stole on again. By this time it was almost pitch dark, and, since the great trees shut off the sky, they had no landmark—not even stars to guide them.

Presently Cyril found he was going downhill, not up. He stopped again.

"I'm thinking we're lost," said Tim.

"It looks like it," Cyril answered. "It may be just a dip. Let's push on a bit and see."

They did push on, but only to find that they were undoubtedly going downhill. They turned again and retraced their steps. The last glimmer of light had gone. They kept stumbling over the cable-like creepers; thorns caught and tore their clothes. The farther they went, the thicker grew the jungle.

Cyril tried hard to keep his nerves steady and his head clear, but every now and then a wave of panic swept over him.

He and Tim had had two very hard days. They were desperately tired, as well as hungry and thirsty, and the fix in which they found themselves was enough to try the strongest nerves.

Blundering through the inky gloom, they suddenly found themselves on a path. It was very narrow—not more than eighteen inches wide—a sort of furrow cut a foot or so deep in the stiff, clayey soil.

Cyril stooped and felt it with his hands.

"It's a path, Tim; a nigger path! Shall we follow it?"

"Yis, but which way? One way will lade us to the village o' thim saw-teeth fellers, and maybe the other will take us up the hill."

Cyril looked up and down and all around, but the giant trees cut off all sight of the sky. He had not the faintest notion which way to turn.

"Let's try the right," he said.

"Wan's as good as the other. Come on, thin!"

There was no room for two abreast, and Cyril was leading the way when, without the slightest warning, the ground gave under him, and, before he could do anything to save himself, he pitched forward and dropped through a thin coating of crackling sticks into a black chasm below

"Look out, Tim!" he yelled, as he fell.

But the warning was too late. Tim had followed him into the pit.

Cyril came down on all fours, on soft wet clay. Tim, pitching on top of him, knocked him flat, and for a moment he was half stunned.

"Are ye hurrt at all?" he heard Tim exclaim anxiously.

"N-no—only a bit bruised. I'm quite all right, Tim. But where are we?"

"'Tis a kind of a well," answered Tim. "Have ye your torch handy?"

Cyril felt in his pocket, and a moment later the bright flash of his electric torch shone on their surroundings and showed that they were at the bottom of a pit some nine or ten feet deep and about five feet square. The sides were perpendicular. Above was the broken roof through which they had fallen.

"Well! This is no well, but a pit trap," said Cyril bitterly. "And we've walked into it like a couple of sheep."

"Thin the sooner we get out, the betther," replied Tim, with a plucky attempt at cheerfulness. "If I heave ye up do ye think ye can catch hould of the top edge?"

"I'll try, anyhow," replied Cyril grimly, and, fixing the torch in the clay, he climbed on Tim's shoulders. He was reaching up for the top when he stopped short and nearly fell back. Looking straight down upon him was a pair of eyes.

The light striking up from below showed that they belonged to the same evil-looking negro whom they had seen watching from behind the bush. Behind him, Cyril caught a glimpse of other tall, dark, shadowy figures.

"Drop me, Tim!" he hissed. It was too late. Quick as a monkey the black man swooped, caught Cyril by both arms and whipped him up.

Tim, when he saw what was happening, reached for his rifle which was leaning against the wall of the pit. Before he could lift it a heavy net was flung down upon him, tangling him in its meshes, and while he struggled desperately to free himself, the man who had flung it leaped lightly down, and caught and pinioned him.

The whole operation was conducted in absolute silence and with the most extraordinary speed. Almost before the boys knew what had happened, their hands were tied behind them, and they were being marched rapidly along the path, which was lit by the glare of a torch carried by one of the negroes.

Its crimson light shone on the tall figures of their captors, and showed them to be all of the same type—tall men, black-skinned, yet, like their leader, more or less Arab in feature.

And, though none were quite so dreadful as the first, to Cyril all seemed to radiate the same atmosphere of evil.

The whole thing was so like a nightmare that Cyril could hardly believe it to be real. His tired brain could not grapple with the situation.

The path now turned definitely downhill, and in a very short time lights twinkled through the trees, and they came out into a good-sized clearing, in which stood a number of huts with conical roofs, looking like large beehives.

Into one of these Cyril and Tim were thrust, and the entrance was closed by poles crossed and lashed with leather thongs. Then, leaving one man on guard at the door, the rest vanished into other huts, and the two boys were left alone in their dark prison.

For the moment Cyril gave way to despair. "Trapped like two silly children!" he muttered thickly.

"Ah, now, what's the matther wid ye?" returned the unconquerable Tim. "Sure, we're alive and no bones broken, and a dry place to slape in. Don't be looking for throuble. Let's take a nap, and thin we'll be able to think what's best to be done about it."

Tim's brave words pulled Cyril together again. "You're right, Tim. After all, we're no worse off than when those Touaregs were charging down on us. We'll sleep on it, and to-morrow perhaps we can find a way out."

"Here's leaves by the wall," said Tim. "Lie down now. Sure, me eyes is shutting in spite of meself."

The two were, indeed, absolutely played out. But they were not fated to get their sleep just yet. A torch glared again, and presently an elderly, repulsive-looking hag was ushered in by a fierce-looking guard armed with a spear. She carried a large wooden platter filled with some steaming mixture which smelt remarkably good.

The woman laid the dish down and left. The guard motioned the boys to eat.

"Smells all right," said Cyril. "And they're hardly likely to try poisoning us. It would be so much easier to knock us on the head. I'm famishing, so here goes."

"I'm wid ye," said Tim. "We'll slape the betther for it."

Each took up a wooden spoon and tucked in. The stew, which was made of meat, green mealies, red pepper and yams, was quite excellent, and they finished it to the last mouthful. Their grisly guardian watched them eat, and to their astonishment actually grinned approvingly. Then he went off, the door was made fast again, and the two were left alone.

There was no more talk that night. They were both so done that they just dropped on their bed of leaves, and knew nothing else until the morning sun, shining through the hurdled door, roused them from their slumbers.

Cyril rubbed his eyes and sat up. The hot rays blazing down on the clearing showed it to be about an acre in extent and to contain some thirty huts. Several women, looking almost as evil as the men, were squatting at a little distance watching the hut. It came to Cyril that they looked like wild beasts licking their lips in prospect of a feed. Seeing the prisoners were awake, the guard signed to one of the women, who went off and came back with bananas, boiled mealie porridge, and milk in a calabash. It was quite a decent breakfast.

"Sure, they're not going to starve us—that's one good thing," observed Tim. "I wondher what they'll be doing wid us?"

Cyril did not answer at once. His eyes were fixed on something hanging in the thick shade of a large tree opposite. He turned to Tim, and his face was oddly white and strained.

He pointed. "That's what they mean to do with us," he said hoarsely. "Tim, don't you understand? They are cannibals."


CHAPTER XV
JU-JU!

FOR a moment Tim stared without speaking. When he turned again to. Cyril his face was a little white under its freckles and tan. But his pluck was unbroken.

"Now we knows why they're feeding us on the fat o' the village," he said grimly.

Cyril did not answer. He was plucky enough, but not so tough mentally as Tim. Tim saw that his friend was literally shivering.

"Hould up!" he said quietly. "They're not going to ate us."

"What can we do?" Cyril asked in a voice that was not quite steady.

"Git away, of course."

"How? They've taken our rifles and our knives. We have no weapon of any sort, and we're under the eyes of that guard the whole time."

"We'll find a way," replied Tim stoutly, and, turning, let his eyes rove over the interior of the hut which was their prison.

It was built of thick bamboos driven deeply into the ground and curiously interlaced, forming a wall which, if slightly elastic, was extraordinarily strong. Even with knives it would be difficult to get out.

At last Tim turned again to Cyril.

"Have ye matches?" he asked suddenly.

Cyril felt in his pockets, then shook his head.

"Not one. I had some in a glass tube, but they've taken them."

"Harrd luck!" said Tim. "I was thinking maybe we could burn our way out."

"Burn it? We'd roast ourselves!"

"Betther roast ourselves than let thim black villains do it," replied Tim drily.

He seated himself on the bed of grass and leaves, and with his chin on his hands remained quite still.

Cyril still fumbled in his pockets.

All of a sudden he gave a quick exclamation. Tim looked up sharply, and the black man outside glared round suspiciously.

Tim noticed this and relaxed again.

"Steady does it," he said, in a low voice. "And what is it ye've found?"

"Something as good as matches," replied Cyril; and if his voice shook a little this time it was with pure excitement. "See here, it's my old burning-glass. I found it in my hip-pocket. Those sweeps didn't notice it."

There was a queer gleam in Tim's eyes as he rose slowly to his feet.

"'Tis the goods," he said. "Wait now till Misther Sootyface calms down a bit. Thin we'll thry it."

The negro seeing nothing suspicious, soon settled himself again.

Tim picked up a small handful of the tinder-dry grass from their bed and rolled it into a tight bunch. Then he took the glass from Cyril. The door faced east and the morning sun blazed in through the bamboo which barred it.

He paused.

"'Tis a risk," he said, more gravely than usual. "'Tis even chances we'll burn ourselves as well as the ould hut."

Cyril's lips tightened.

"Go ahead!" he said determinedly.

Tim quietly focused the glass, and almost instantly the dry grass began to smoke.

"Look out!" whispered Cyril sharply "Sootyface is watching."

Turning his head, the negro had caught sight of what Tim was doing.

"No matther!" answered Tim. "He'll not interfere wid us."

He was right. The negro's jaw had dropped, and his eyes were fixed in a glassy stare of terror. Never in his life had he seen the rays of the sun used to start a fire, and the whole operation was to him the blackest of black magic. It was ju-ju such as even his own medicine man had never attempted, and he was so scared that for the moment he was actually paralysed.

The bundle of grass flared into flame. Tim took three quick steps across the hut, and flung it right into the piled-up straw.

It caught like powder. A six-foot flame burst upward and roared fiercely against the wall.

"Hould your coat over your face," cried Tim, at the same time whipping off his own. It was time, too, for the heat was enough to skin the inmates of the hut. They shrank back against the barriers of the door, gasping for breath. Luckily for them, there was a slight breeze blowing in from outside to give them air, but for all that Cyril felt as if he was being roasted alive.

The pain was intense. He could smell his clothes and hair singeing.

Then with a roar the roof caught and flew upward in a crackle of fizzing sparks.

Now the heat was like that of a blast-furnace. Cyril dropped to his knees. He could no longer stand.

He was vaguely aware that Tim had both arms out between the bamboo bars which were lashed across the door. Then he lost consciousness.

The next thing he knew was being dragged forward.

"Can ye walk?" hissed Tim in his ear. "Ah, if ye cud only run, we'd do it yet."

With a tremendous effort Cyril rallied his failing forces. His legs felt weak as water, yet Tim's words had acted like magic.

"I can," he gasped. "Where are we?"

"Outside. Not fifty steps from the woods, and the niggers are scared stiff. Hould yerself up and we'll thrick thim yet."

With Tim's arm round him, Cyril staggered forward. The air, hot as it was, seemed ice-cool compared with the furnace from which he had escaped. His strength came back a little, and sight to his scorched eyes. Just in front was the solid wall of bush. Next moment they were in it, and under its mysterious shade.

Still Tim dragged him on. They were running down a steep slope where, for a wonder, the undergrowth was comparatively thin.

On and on they went, with their tongues hanging out of their parched mouths and their hearts thumping against their ribs—on until, to save their very lives, they could run no farther, and both dropped together among the coiled roots of a gigantic tree. There they lay, panting for breath, with the sweat streaming down their blistered faces.

"Are they after us?" Cyril asked at last, in a hoarse whisper.

"I don't know," panted Tim. "I can't hear thim, anyway. I'm thinking they'll lave us alone a while. It's scared they were—scared bad."

"But they'll get over that. They're bound to follow."

There was silence for a full minute. Then Cyril spoke again.

"How did you do it, Tim?"

"Sure, I got hould of that blackamoor's spear. He dhropped it when he ran, and I could just rache it. Thin I cut the lashings an' dragged ye out."

"You saved my life, Tim."

"Arrah, don't be talking! What's our lives worth this minnit?"

Cyril was silent again. Come to think of it, Tim was right. Although for the moment they had both their lives and liberty, they were in danger of losing both.

They had no weapons of any sort, no food, no drink, no compass or matches, they were hopelessly lost in the heart of a tropical jungle, and probably at this very moment being tracked by saw-toothed cannibals, wild beasts in human shape.

Presently Tim sat up straight. He was listening hard. Then he laid himself down and placed one ear against the ground.

"We'll be moving," he said briefly. "They're afther us."

The short rest had given them their second wind; they ran faster than before. The slope grew steeper. Cyril knew in his heart that they were getting farther and farther into the depths of the great basin, nearer to the lake that was in its centre. But there was no choice. The cannibals were between them and safety.

Soon his strength began to fail again. The heat of the fire seemed to have sapped every atom of moisture from his body, and he suffered tortures from thirst.

Glancing sideways at Tim, he saw that he, too, was suffering in the same way.

He looked back. At first he could see nothing of their pursuers, but suddenly a sinister black shadow shot out from behind a thick trunk, and a polished spear-point gleamed in a vagrant ray of light. The sight spurred Cyril to fresh efforts, and he ran harder than ever.

A tree-trunk lay in his way.

"Look out!" he heard Tim cry hoarsely; and saw him jump high into the air. He too, leaped, just cleared it, and, slipping as he landed, fell on his face in a patch of ground so wet that the water splashed in his face.

At the same moment he was conscious that the tree-trunk was moving. He glanced backward as he lay.

The trunk was no trunk, but the monstrous body of a snake bigger than he had ever even dreamed of.

Cyril tried to struggle up, but Tim's hand was on his arm.

"Lie still," he muttered. "'Tis our wan chance."

And Cyril, who was almost beyond caring what happened, lay still and listened with creeping flesh to the slow dragging of the great serpent, drawing his vast weight through the thick grass.

It seemed to go on for long minutes, and while it lasted he lay as still as if frozen. At last the sound ceased, but even then he did not dare to move.

But now he heard something else, and, glancing at Tim, saw him lapping up water like a dog from a tiny pool which had formed among the grass roots. He realized that he himself was soaking wet, and that water was oozing out of the ground beneath him. He drank greedily, and the relief of it was so intense that, for the moment, he nearly forgot all else.

But when his thirst was quenched recollection came back, and he ventured to glance over his shoulder.

What he saw was so extraordinary that it left him breathless with amazement.

The serpent had moved away to a distance of perhaps twenty yards—certainly not more—and had coiled itself into a mound of heaped-up rings, gleaming with a splendour of colour. The play of rainbow tints on its shimmering skin was so wonderful that, in spite of his horror at the reptile's size and strength, Cyril was fascinated by its amazing beauty.

Above the coils its great head was lifted a yard or more on a column of neck thick as a man's leg, and the creature seemed to be watching something in front of it, something which at first Cyril could not see.

Very slowly and cautiously he dared to raise his head, and then at last he saw.

Flat on their faces, with their clasped hands stretched out in front of them, lay about a score of the saw-toothed cannibals, and by the twitching of their muscles Cyril knew that one and all were in the last extremity of terror.

He touched Tim, and pointed; he did not dare to speak.

Tim looked, nodded, and beckoned. Then he began to crawl away through the grass, and Cyril followed.

Once he looked back, but the snake had not moved. After that Cyril and Tim devoted all their energies to putting as much space as possible between themselves and the shining, terrible monster. They did not stop until they had crossed the glade, and were in the dark shade of the bush beyond.

Then at last Tim stopped.

"May I be burned if iver I say a word against a snake again!" he said emphatically. "'Tis him that's saved us, Cyril."

"I know it. So long as the python doesn't move I don't believe the niggers will."

"I'm sure of it," responded Tim. "And now where will we go?"

Cyril looked round. Through a rift in the trees he caught a glimpse of the rugged rim of the great cup in which they stood. It seemed to be miles away, and he realized that they could not be far from the lake-bottom and the lake which filled it.

"I vote we go and call on Kent," he said recklessly. "He can't be far off."

"Just what I was going to suggest meself," answered Tim calmly. "Come along wid ye."

So the two, unarmed but unafraid, walked straight down the steep slope.

They had not gone more than two hundred yards before Cyril, who was leading, stopped short and pointed. Through a break in the forest a great sheet of water was visible. It was the lake.


CHAPTER XVI
THE CROOKED HOUSE

"AND now we know where we are," said Tim, with a sigh of relief.

Cyril did not answer. He was staring with puckered brow out across the great sheet of water. It was even larger than he had thought, for the trees on the far side looked quite tiny. Its colour was greenish-blue, and it was evidently of immense depth.

"It's the crater of a dead volcano," he said thoughtfully.

"Not so dead, maybe," returned Tim, and pointed as he spoke to a plume of feathery vapour which rose at a little distance to the left.

"A hot spring!" exclaimed Cyril. "Let's have a look at it."

The spring spouted up from a small cone of whitish limestone, and fell into a basin so round and perfect it looked as if it had been carved by man's hand. Trickling over the edge of this, it ran in a dainty little stream down to the lake below.

"Hot water on tap. All modern convaniences," said Tim, with a grin.

Cyril looked longingly at the clear water.

"Tim, do you think it would be safe to bathe? We haven't had a wash for forty-eight hours."

"Sure, it would be just as safe as what we are doing," responded Tim. "Strip and get in wid ye. I'll kape a watch."

"Let's hope it will turn out better than our last bathe," said Cyril, rather grimly. He was thinking of the time the Touaregs had swept down on them. That was four days ago, but it seemed like four years.

There was a tiny pool just below the terrace. The water was about six feet deep, clear as crystal, the colour of a thrush's egg. Cyril felt it with his hand. It was hot, but not too hot, and in a trice he had slipped off his clothes and slid in.

He drew a long breath of pure delight.

"Tim, it's wonderful!" he said. "Puts new life into you. My word, if we had this spring in England it would be worth a fortune!"

There was a rather twisted smile on Tim's lips.

"It's a dish of bacon and eggs I nade to put new life into me," he remarked.

Cyril laughed out.

"You're a greedy pig, Tim. After all, we did have a breakfast."

"I'd feel happier if I knew where supper was coming from," said Tim. "And now, if ye've had enough, I'll be thrying your warm bath."

Cyril came out, and Tim went in.

"I'll not be denying it's fine wather," he admitted.

"It's wonderful!" declared Cyril. "I feel fifty per cent, better already. It's taken the bruises and stiffness out like magic."

"But not the hungry feeling out of me," returned Tim ruefully, as he splashed about. "It's meself is wondhering where our supper's coming from."

"I thought we'd agreed that Kent was to provide that."

Tim climbed out of the pool, and dried himself with a handkerchief.

"Sure I know we talked that way, Cyril," he answered soberly; "but, afther all, we're not quite crazy. In the first place, we haven't the least notion where to look for the spalpeen, and even if we find him, what'll we do widout guns, or so much as a knife between the two of us?"

"I'll allow it's a bit of a teaser," Cyril replied; "but it seems to me we've got no choice. I don't suppose you feel like facing those cannibals any more than I do, and there's no way out of the mountain without passing through them. Another thing, we can't be far off Kent's place. You know his airship is on this side of the lake. Seems to me the best thing we can do is to work along the edge of the lake till we see the airship. Then we shall know where we are."

Tim shrugged his shoulders.

"Maybe we will, maybe we won't. But 'tis as good a plan as any. Come on, thin."

They went very carefully. Always at the back of their minds was the feeling that those filed-tooth cannibals might swoop down upon them. Even so, the forest was so wonderfully lovely that they could not help stopping sometimes to admire it.

The trees were magnificent. They soared up a couple of hundred feet or more, and the trunks of some were ten feet through. From their branches hung creepers covered with the most gorgeous purple flowers with yellow or black centres, and higher up great air-plants and orchids hung.

Immense butterflies, looking as if they were cut out of blue silk and gold tissue, floated by. There were birds, too, of gorgeous plumage, and of sorts which Cyril had never seen before.

"'Tis fairyland, as ye said," remarked Tim. "If only we cud get rid of thim black fairies."

"We've got to get rid of Kent first," answered Cyril, as he pushed through a thick line of bush which barred his way.

Then he stopped short.

"There he is," he remarked quietly.

"Is it Kent, ye mane?" questioned Tim, coming up quickly behind.

"Kent himself," replied Cyril quietly. "There—on the pontoon. Do you see?"

"You're right!" gasped Tim, staring.

They had come out quite suddenly on the eastern edge of the bay which they had seen three evenings earlier from the observation platform of the "Avenger," and found themselves among the trees on a low bank facing the inlet.

Exactly opposite, and apparently not more than two hundred and fifty yards away, lay a great pontoon built of logs and anchored close to the opposite shore, on which reposed Kent's airship. And standing on the pontoon, but with his back to the watchers, was a hulking figure in a white suit.

Tim stood glaring at Stella's kidnapper. Then he turned to Cyril.

"If I only had a rifle!" he groaned.

"But we couldn't shoot him in cold blood," remonstrated Cyril.

"Is my blood cowld, do ye think, whin I look at that blackguard and thafe?" retorted Tim fiercely. "Faith, 'tis boiling it is in me veins this minnit."

"We haven't got rifles, so we must find some other way," said Cyril quietly. "Keep down, Tim. He mustn't see us."

"No, but we'll see him, and what skunk's hole he hides in," growled Tim. Cyril had never seen the Irish boy so stirred.

Crouching in the bushes they watched, and saw Kent walk all round his airship, apparently examining her to see that all was right. Seemingly satisfied, he got into a small boat and pulled back up the inlet.

Now Cyril and Tim saw what—in their eager watch on Kent—they had not noticed before. This was a great mass of building at the inner end of the small bay, an enormously solid and heavy building of huge stones, partly ruinous and evidently very ancient.

Strange it was to see such a gigantic work of masonry in this forsaken spot, but stranger still was the fact that the whole vast pile lay at a slope, so that part of it was actually under water, and the whole thing had a curious appearance of being about to slide bodily into the lake.

Cyril stared at it for several seconds.

"Why," he said slowly, "it's Assyrian. It's just like a picture I've seen of an old Assyrian temple. Look at those thick, short columns, and the queer beasts carved on them."

"'Syrian, is it?" replied Tim. "Sure, I hardly thought Kent cud have built it in the time!"

In spite of everything, Cyril smiled.

"My dear Tim, the people who built that have been dead two thousand years—perhaps three. But think what a piece of luck for Kent! It's a regular fort!"

"Wid the front door under wather. 'Deed, but I'd hate to live in a place like that. I'd feel as if I'd be dhrowned in me bed."

"The landslip's an old one. I dare say it's been like that for hundreds of years. Let's see how he gets into it."

Kent pulled to the right, and he and his boat vanished into an opening. The boys waited, but there was no sign of his return—no sign of movement of any kind.

Complete silence had fallen on the woods and lake, which slept under the midday blaze of the tropical sun.

At last Tim spoke again.

"'Tis no use waiting here. Let's be going round a bit. If the ould place hasn't a front door, maybe it has a back one."

This suggestion sounded reasonable, and, going back a little from the edge of the bay, the pair made their way slowly and cautiously in a wide semicircle inland. Among the trees the ground was littered with large stones, some of them nearly buried in the ground, and many curiously cut and carved.

"Must have been a regular city here in the old days," said Cyril, in a low voice.

"Sure, I'd give it all for a ham-and-beef shop," replied Tim, who was always hungry, and who, after all the excitements of the morning, was feeling an aching void beneath his belt. Cyril, too, was hungry, but was too excited and interested to feel it as badly as Tim.

Presently they came upon a ruined wall almost hidden by thick creepers. Bright-coloured lizards lay basking on the hot stones, and a small reddish snake writhed away into the thicket. They found a gap and passed on.

Then Tim, who was leading, stopped short. Cyril saw that he was peering down into a hole in the ground.

"'Tis another o' thim pit thraps," he said uneasily. "I'd not have thought thim blackamoors would have come so close to Kent's place."

Cyril stepped up to the edge of the hole. It was of a most curious form, being small at the mouth and bulging out below. In fact, it was shaped like a water-bottle. The bottom, which was about ten feet below the level of the ground, was paved with large stones, and the sides were built up of masonry.

"The niggers never made that," said Cyril. "It's a slave pit."

"A slave pit?" repeated Tim, puzzled.

"Yes. I've seen pictures of slave pits found down at Zimbabwe, that ruined city in Rhodesia, and this is just like them. Zimbabwe is supposed to have been built by the Phoenicians, and they used to keep their slaves during the night in pits like these."

Tim grunted.

"A swate lot they must have been!"

"No worse than Kent," said Cyril. "I say, there's a break in the trees just beyond. Go quietly."

Sure enough, they were on the very edge of a clearing—quite a recent clearing, too, for the bare and jagged stumps of newly-cut trees stuck up in every direction, and there were dark patches here and there where the branches had been piled and burnt.

The clearing was about a hundred yards wide, and in full sight on the far side was the same monstrous pile of buildings which they had seen already, only now they were looking at the back of them instead of the front. Now that they were closer, they could see more plainly the massive character of the masonry.

Each stone would have been a big load for a railway-truck. What was more, they were so beautifully joined that the lines between them were only just visible.

"There's the back door all right," observed Tim, pointing to a wide square doorway with pylons thick as a great tree-trunk on either side.

"But no use to us," returned Cyril bitterly. "Look at the barbed wire!"

Sure enough, a fence of six strands of heavy barbed wire, looking ridiculously modern and incongruous amid such surroundings, ran in a great semicircle through the clearing. It had no gate in it, or opening of any sort.

Tim stared at it in silence for a while.

"And what'll we do now?" he asked disgustedly.

"Wait till dark," replied Cyril.

"And where will we wait?"

"I'll show you," came a deep voice, and both boys, swinging round with startled faces, found themselves confronting a complete stranger, a big, gaunt, white man, with a long beard. He wore rather ragged clothes of tropical drill, thick boots, and gaiters. On his head was a huge green cork helmet, and he carried a heavy-bored rifle.

"I'll show you," he repeated. "Come with me!"


CHAPTER XVII
THEIR NEW ALLY

CYRIL stared at the stranger.

"And who are you?" he demanded.

"No friend of that man," replied the other harshly, and he pointed to the building by the lake.

"And how do you know that we are not?" asked Cyril.

The big man gave a short, sharp laugh deep in his throat.

"I happen to have been following you for the last hour," he answered.

"Ah!" said Cyril quietly. "Then you have overheard what we were saying?"

"Exactly," was the dry response.

"And may I ask where you come in?" questioned Cyril.

"You may. My name is Tudor Trench. I am interested in antiquities and in big game. I found this place two years ago, and came back here with stores, intending to make a long stay and study these strange remains. I was attacked by Karalek cannibals, my men were killed, and I only got away by the skin of my teeth and the free use of this"—he tapped his heavy rifle as he spoke. "And here I have been for more than a month, living like a rat in a hole."

He scowled as he spoke, and his voice was very bitter.

By this time Cyril felt quite sure that their new acquaintance was genuine.

"If you will take us to your 'hole,'" he said, "we will tell you how we come to be here. And if you can add to your kindness by giving us something to eat we shall both be tremendously grateful."

The other smiled grimly.

"Oh, I have plenty of food!" he answered. "That's one thing they can't cut me out of. This way." He turned as he spoke, and went off through the trees.

Cyril and Tim followed, Cyril wondering how on earth their new friend had managed to subsist with Kent on one side and the cannibals on the other.

The trees grew thicker; the path led a little uphill. It ended quite suddenly in a sheer face of rock.

The big man turned.

"Can you climb?" he asked briefly.

"Like a squirrel, if there's dinner at the ind of it," answered Tim.

"Cold roast meat, biscuit, and fruit," was the answer. "Come on, then, but be careful to follow exactly where I go. It's not dangerous, but it's awkward."

Seizing a tough creeper he swung himself to a ledge a few feet up, and began to climb. The ledge, hardly more than a foot wide, zigzagged up through masses of creepers and thick, stiff bushes.

"Awkward!" muttered Tim. "I wondher what he'd call really hard?"

Luckily, it was not very long. They were only about fifty feet up when their guide, swinging himself round a knob of jutting rock, vanished into a hole in the cliff face.

Following him, the boys found themselves in a short tunnel, through which they had to creep on hands and knees. Cyril, who was leading, saw light ahead, and all of a sudden found himself in a cave the size of a large room, and lighted from above by a wide opening running slanting out to the rock face.

The place was furnished with a camp bed, a folding table and chair, and one packing-case.

"This is my rat-hole," said their host. "Sit down. You'll have to sit on the floor. Here's meat"—he took a large cold joint from under a grass-woven mat. "Biscuits are in the packing-case. Here are plantains and wild guavas."

"Sure, I'd have climbed farther to fare worse," said Tim, as he set to on the cold meat and biscuits. "'Tis an elegant joint this, sorr, but what animal would it be from?"

"It's hippo beef," answered the other, and smiled again. It was a nice smile, Cyril decided, and gave their host's harsh, saddle-tanned face quite a pleasant expression.

Cyril, too, set to work on the beef, which was excellent, but, hungry as he was, he was too anxious to hear about things to remain silent.

"What puzzles me, sir," he said, "is how you escaped the cannibals when you first came here."

"There weren't any," was the surprising answer. "They have come since, and, if you ask me, it was this man with the airship who imported them. He is hand-in-glove with the brutes."

Cyril's eyes widened. He could hardly believe his ears.

"He brought them? Kent brought them?" he gasped.

Trench paused, with a banana half-way to his mouth.

"That is my deliberate opinion," he said. "They belong to a race which lives on the edge of the great forest three hundred miles south of this. How this man you call Kent got them here I do not pretend to explain, but the fact remains that they were not here two years ago."

"Was he here?"

"No, but he had been here. I found traces of recent occupation in the Phoenician palace. I presume he had reached the spot by aeroplane or dirigible, and, finding it suited to his purpose, had begun to prepare for its occupation. No doubt he collected the Karaleks as watch-dogs."

"But they are cannibals. Why didn't they eat him?"

Mr Trench shrugged his broad shoulders.

"This man knows more than a little about Africa and its natives. He talks their language better than I do. He has bargained with them in some way.

"Now," he added, "be good enough to tell me what you know about this fellow, and what you have had to do with him; it surprises me to find two youngsters like yourselves after him."

"Oh, we are only scouts—Tim and I," replied Cyril modestly. "My father and the rest of our party are camped to the west of the mountain, where the river runs out. The reason we are after Kent is that he has stolen Stella Earle, who is the niece of Mortimer Carne."

"The ironmaster?" put in Mr Trench quickly.

"Yes."

"A bad man to cross," said the explorer; "but go on."

So Cyril told the whole story—how Kent had stolen the model of Mr Hamer's airship, built his ship somewhere on the Continent, then come back and kidnapped Stella. He told of his abominable threat to hand Stella over to the savages if the ransom were not paid, of how the "Avenger" had been built with Carne's money, and the hunt across the desert to reach, at last, the Mountain of Death.

"So you see, sir," ended Cyril, "it was jolly good luck for us meeting you, for if we hadn't I don't know what we should have done."

The big man brought his palm down with a crash upon his knee.

"Upon my word," he said, "I think the luck is on my side. You are lads after my own heart, and between the three of us I think we may do something to drive this scoundrel into a corner."

He paused.

"Now tell me," he said presently, "what arrangements have you made for communicating with your people and the airship?"

Cyril's face fell.

"That's the trouble, sir. We were to have been back at the foot of the mountain not later than this evening. The men who came with us left stores for us under a rock, and a wireless installation. We were to call the airship up if we needed her, or, if we thought better, our aeroplane. You see, we were only to scout. We never reckoned on those cannibal brutes."

"Just so. And now we seem to be cut off completely," said the explorer. "Yes, it is an awkward business, for even I—well as I know the valley—would not care to risk climbing out of it. As a matter of fact, these Karaleks keep a pretty close eye on me."

"Why don't they come down and attack you—that's what I've been wondering?" said Cyril.

The big man put a hand into the pocket of his Norfolk jacket and took out a long, heavy cartridge. "Four fifty," he said, holding it up between finger and thumb; "hollow nose. Knock a hole as big as my fist through three men at once. I used six of these the last time they tried to raid me, and the hyenas had a feast that night. I don't think they will try it again in a hurry."

"'Deed, thin, I wish ye'd been able to use sixty," said Tim. "It's claner the place wud be if the last wan o' thim sharp-toothed vermin was fed to the wild bastes."

"I quite agree with you, my young friend," answered Mr Trench. "But the question before us now is how to deal with this scoundrel Kent. Has either of you any suggestions to make?"

There was silence for some moments while the three looked at one another—a silence that was suddenly broken by a harsh, clattering noise.

Like a flash Cyril was on his feet, and hurrying down the tunnel which gave access to the lake. The others followed.

Cyril was at the mouth. He was pointing out in the direction of the lake. "Kent's engines," he explained quickly. "He must be going off on another trip. I wonder if he has heard of us from the Karaleks, and is going to look for us?"

"Quite likely," said Mr Trench quietly; "but as you say your airship is camouflaged, he will hardly be likely to find her. And as for yourselves, hidden here as you are, you need hardly be nervous about discovery."

Tim broke in breathlessly.

"But if he goes out, isn't it our chance he's giving us? Why wouldn't we be paying him a visit while he's away?"

Mr Trench laughed deep in his throat.

"A bit of a bull, Tim, but I quite see your point. I presume Kent will need most of his men to navigate his craft, and it certainly seems a good opportunity to make a raid on his stronghold. The difficulty is the wire which, I believe, is electrified. And I have no insulating gloves or cutters."

"Why wouldn't we swim round the ind of it?" suggested Tim. "Sure, we'll get round some way or another."

"I don't know about swimming. There are queer beasts in the lake. But we'll have a try, anyhow," said Mr Trench quietly. "First, however, let us be sure that the fellow is really off, and not just trying his engines."

They had not long to wait. In about a quarter of an hour the airship floated smoothly up above the trees, and sailed away westward down the lake.

"He's on our thrack right enough," said Tim seriously.

"Don't you worry, Tim," replied Cyril. "He'll never find the 'Avenger,' and even if he did the 'plane will be ready to tackle him. Jove, I hope they get him!"

"I wondher if he's got Miss Stella aboard?" said Tim.

"Not likely. The chances are she's hidden somewhere in that old palace this minute. What a sell for Kent if we could only find her and get her out."

"You've that barbed wire to tackle first, my son," said Mr Trench drily. "Come back and sit down. We can't start till dusk, and that's another hour yet."

The boys were desperately impatient, and that hour dragged horribly. But it passed at last, and there was no sign of Kent's return. The sun had set and the short dusk was deepening over the broad lake as the three clambered down the steep rock face, and presently found themselves safe in the forest below.

Mr Trench led the way. For all his bulk he moved as quietly as a panther among the towering tree-trunks. The night life of the forest was awake—frogs croaked, crickets shrilled, and out on the lake heavy splashes told of great fish feeding.

Presently they were out in the open space among the newly-cut tree stumps. They paused, but there was no light from the great gloomy building which squatted on its tilted shelf by the lake.

"Go quietly," said Trench in a whisper. "We don't want to run into that wire. We may start some electric alarm. I fancy Master Kent has gone the whole hog in the matter of protecting himself."

They crept on very cautiously until Trench, who was leading, stopped.

"Here's the wire," he whispered. "Wait now."

He took out a hunting-knife, wrapped the handle in an old silk handkerchief and stretched out his arm toward the wire. There was a sharp crackle, and a blue flash snapped out into the darkness.

"I feared it," growled the big man in his throat. "The wire is electrified. We can't touch it without insulators, and we have nothing of the sort. What is to be done?"


CHAPTER XVIII
TAKING CHANCES

"WILL we creep along down it, and see if we can get round the ind?" suggested Tim.

"It runs right into the lake," Mr Trench told him. "And much as I should like to get inside the enclosure, I'd not trust myself in the water. There are beasts there that don't belong in the natural history books."

Cyril shivered slightly. The idea of the deep, dark water and its unknown inhabitants daunted him.

"I suppose there's not a tree left that hangs over the wire anywhere?" he asked.

"There's nothing of the sort," answered the explorer. "I have made sure of that. Kent may find these Karaleks useful as police, but he is not taking any chances of their getting inside. He'd as soon trust a pack of wolves."

"Faith, I don't blame him," said Tim. "Not from what I've seen of thim. But what'll we do at all? We can't be sitting here all through the night."

"Upon my word, I don't know what to suggest," said Mr Trench. "Unless, indeed, we try to burrow under the wire."

"It seems the only thing to try," answered Cyril. "But we haven't so much as a spade, and I don't quite know how we are going to do it without one."

"There's plenty of loose wood about," said Mr Trench. "With my knife we might hew out a couple of rough shovels. After all, the soil is not very hard."

"'Tis that we'll do," said Tim with decision. "And a pity it is that we didn't think of it before."

As he spoke he was groping about in the darkness. Sure enough, the ground was littered with branches and large splinters from the trees which Kent had felled. Much had been burnt, but there was plenty left. Very soon Tim had found a useful length, and their new friend was busy sharpening the end with the blade of his big hunting-knife.

At the end of a quarter of an hour it was ready, and Tim took it and set to work. Cyril, meantime, had found a second piece, and this Mr Trench tackled.

Soon Cyril was busy alongside Tim, and the two made the soft earth fly. Yet it was slow work, for they dared not use a light, and they had to be desperately careful not to touch the wire. From the spark drawn from it by Mr Trench's knife-blade it was quite evident that it carried a very heavy load, enough, probably, to kill, or at any rate stun, anyone who touched it.

Besides that, the soil was full of roots, and the moment they got below the surface they struck a perfect network of them. Mr Trench had to use his knife to cut them one by one.

An hour passed, and they were not two feet down, and the roots they encountered grew thicker and heavier the farther they went.

Their hands were sore, and perspiration poured down their faces. Into the bargain this low ground by the lake swarmed with mosquitoes of a particularly venomous brand. They bit cruelly. Their hands and faces were almost covered with the detestable insects, and Cyril knew well enough that the pain and discomfort they caused were the least of the danger, for the bite of these swamp mosquitoes brings malaria, and even worse things, in its train.

It was Tim who stopped and wiped his streaming face.

"Here's a root as thick as me leg and twice as harrd," he said. "'Tis an axe we'll be needing to get through it."

"You're right, Tim," agreed Cyril gravely. "This is beyond a knife to cut, and at the present rate it will be daylight before we can finish our tunnel under the wire. What are we to do, Mr Trench?"

Mr Trench straightened his aching back.

"I'm very much afraid you are right, Cyril. The job is beyond us without proper tools. We must try and find some place where the ground is free from roots, and, if not, our only chance is to take to the water."

In spite of the heat, Cyril shivered again. The idea of the lake, with its strange inhabitants, was terrifying. Cyril had plenty of pluck to face any danger that he could see, but to swim in that dark water with the risk of being plucked down by some denizen of the depths was enough to terrify anyone.

"Let's try for a softer place first," he said. "If we could only have a light it would be so very much easier."

"Quite so, but a light is out of the question," returned the big man. "Let us move quietly along the wire to the right. I think that, nearer the lake, there may be more open ground."

He moved off slowly, and the boys, carrying their wooden shovels, followed. The ground was rough and covered with stumps, and there was always the danger of running into the wire. They had to go very slowly.

For a couple of minutes, perhaps, they crept forward. Suddenly from the direction of the lake came a loud splashing sound, and then a deep snort.

Mr Trench stopped short.

The snort was followed by a loud crashing and trampling.

"Steady!" said the explorer. "It's a hippo coming out of the lake. We'd best look out or he may trample right over us. They're clumsy brutes, hippos."

Though a hippopotamus is not a ferocious animal it is a very big one, and the old bulls are apt to be very queer-tempered. It was not altogether a pleasant situation in which the three found themselves, standing there in the darkness with this monster waddling across the open ground and coming apparently straight toward them.

"We must find cover of some sort," whispered Mr Trench in Cyril's ear. "Look out for a fallen tree."

They backed away carefully, and presently Cyril stumbled against something in the darkness.

"Here we are," he said. "It's a good big trunk. We can all get behind it."

They did so without delay.

"All I wish is 'twas twice as big," muttered Tim.

"Don't trouble yourself," said Mr Trench. "He'll hardly cross this, even if he bumps into it. In any case, he can see a great deal better than we can."

"What's he afther?" asked Tim.

"The green corn they've got planted inside the enclosure. Your friend Kent has made every preparation for a long stay. He has a regular garden inside the wire."

"It must take a good fence to keep out beasts like that," said Cyril, as the trampling sounded nearer. "He must be a whacker. I say—suppose he tackles the fence?"

The words were hardly out of his mouth before a bright flash lit the gloom.

"He's touched it!" said Cyril in a sharp whisper.

No one heard what he said, for next instant came a bellow like nothing on earth, a trumpeting roar worse than that of an angry elephant. It was followed by a tremendous twanging.

"He's into it!" cried Tim. "The baste is into it!"

Into it he was, without a shadow of a doubt. The shock—and even for a beast the size of a hippo the shock must have been a heavy one—had turned his blundering good nature to sudden fury, and Master Hippo had flung the whole of his two or three tons of bone and flesh against the barbed-wire fence.

Fresh flashes darted forth, but only for a second. The next, the thick wires parted with a series of resounding twangs, and a deep crunching of uprooted posts.

Tim raised his head.

"Good luck to him! The baste has done the thrick. He's finished our job for us. Sure, we've nothing to do but walk right through."

Mr Trench's heavy hand fell on Tim's shoulder.

"Down, you idiot! Don't you realize that this will bring out every soul in the place?"

He was right. Almost instantly lights flashed out from the land side of the old palace by the lake. A blinding ray came sweeping across from a doorway or window, wheeling across the garden, and the open ground behind, casting a white glare on the log behind which the boys and Mr Trench were hidden, and coming to rest upon the cause of all the disturbance.

Peeping over the rim of their refuge, Cyril was witness of the most amazing spectacle upon which his eyes had ever rested. The hippo, a monster as big as an average elephant, and probably weighing six or seven thousand pounds, had gone through the great six-strand, barbed-wire fence as if it had been so much packthread. But in doing so several strands of the wire had got wrapped around his huge body. Thick as his hide was, the barbs had evidently penetrated it, and the smart of them, combined with the sharp electric shock, had driven him frantic.

Now he was plunging back toward the lake, dragging half the fence behind him. With every plunge fresh posts went, breaking with cracks like pistol-shots, while the coils of loose wire whipped up and down, and twisted afresh round the tortured body of the colossus.

"Keep down!" warned Mr Trench again. "They'll be shooting in a minute."

Again he was right. From the front of the palace two rifles opened at once, and a volley of bullets thudded against the mad monster.

If Kent's men had hoped to save their fence they were mistaken. The fresh wounds seemed only to drive the hippo more crazy than before. He fairly galloped toward the lake, raking the posts and wire away as easily, and far more quickly, than a tank would abolish a Hun entanglement. Twice he came down on his head with a thud that shook the ground.

And still the light followed him, the rifles cracked, and the bullets thudded on their living target.

Then he reached the edge of the lake, and with one devastating rush went over. There was a splash like the launching of a battleship, and spray glittered golden in the searchlight's glare. Dead silence followed. The monstrous beast was gone, and with him the better part of a hundred yards of Kent's carefully-prepared defence.

Angry voices broke the stillness, and two men came running out to inspect the scene of the damage. The light was no longer on the log, and Cyril ventured to peep over.

They were white men, but hard-faced, ruffianly-looking fellows, dressed in workman's blue overalls. One had a rifle, the other carried a heavy pistol.

"Here's a nice job!" snarled one. "We'll have them blacks in here, a-cutting our throats, next thing we knows. Pretty taking the boss will be in!"

"'Tain't our fault, anyway!" returned the other. "So he can't say nothing to us about it."

"Can't he?" retorted number one, who was evidently very much upset. "He'll say we'd ought to have shot the brute afore it started the job. See here, Jonas, we'll have to mend this up some way."

"What—to-night?"

"Yes, to-night!" snapped the other. "There's plenty o' wire inside. We'll run two strands across and connect 'em up with the dynamo. I ain't a-going to have them niggers inside the place, not if I knows it. And there ain't nothing to stop 'em once they get into the garden."

"All right," said the man called Jonas, in a sulky tone. "Tell Ben to keep the light on. I'll come along and help you get out the wire."

The pair turned, and went back toward the pillared doorway of the palace.

Cyril was on his feet in a flash.

"Now's our chance, Mr Trench!" he whispered sharply.

"To get in, you mean?"

"Yes, they'll be some minutes getting that wire. We shall have plenty of time to slip through into the garden before they come out again."

"I believe you are right," replied the big man quietly. "Come along then. But if the searchlight shifts drop quickly."

Rising to his feet, he stepped over the log, and led the way. Cyril followed, and, close behind, Tim. Cyril's heart was thumping, but with excitement, not fright.


CHAPTER XIX
INSIDE THE PALACE

THE searchlight's beam remained stationary, and, keeping just out of its glare, the three crossed the fence—or, rather, the line where the fence had been—and reached the garden inside.

Here were rows of sweet com, or garden maize, standing eight or nine feet high. They slipped behind its shelter and took stock of their surroundings.

"There's only one way in or out, as far as I can see," whispered Cyril.

"The main entrance between the pillars," replied Mr Trench. "You are right, I believe. The whole of the rest of the front of the building seems to be blank. But there's sure to be an entrance on the side facing the lake."

"These men can't reach that without a boat, and the boat is probably moored alongside the float in the lake," said Cyril. "Anyhow, there's no way for them to go round."

"No, they can't get round without swimming, and I don't fancy they'll be any keener than we to try that sort of thing," responded Mr Trench. "I'll tell you what, Cyril, the best thing we can do is to stay where we are until these fellows come out again and get to work on the wire."

"And then make a rush for it?" questioned Cyril.

"Just so. The chances are they won't see us."

"But won't the searchlight man be seeing us?" put in Tim.

"No need for him to do so," said Mr Trench. "The light is being worked from an opening over the main entrance. We ought to be able to creep in under it."

"I take ye, sorr," said Tim. "But don't be talking any more. Here they come."

As Tim spoke, the two men appeared again, coming out of the main entrance. They were heavily loaded with coils of wire and tools, and both appeared to be in a very annoyed frame of mind.

"I told the boss it was asking for trouble, to plant all this truck inside here," said one.

"Much notice he'd take of what you said, Jonas," sneered the other.

"Much notice he takes of what any of us say," growled Jonas. "I tell you, Mark, I'm getting fed up with Bertram Kent."

"What's the use of talking like that?" retorted the man called Mark. "Even if we wanted, we couldn't leave till he gets ready to go. And you can't say he don't pay well."

"Oh, the money's all right," said Jonas sulkily. "It's only that I'm sick of loafing in this forsaken hole, where there's no one to talk to, and nothing to see but trees and water. I'd give a month's money to walk down Old Kent Road or get inside a picture palace."

Mark gave a harsh laugh. "There's more'n picture palaces to see without going that far. Haven't you never been down in the glass room?"

"Ugh!" grunted Jonas. "Once I have, but never again. The things you sees down there is enough to give a chap bad dreams for a month."

"They ain't pretty or nice, and that's a fact," agreed Mark.

Cyril was listening with such interest that he almost forgot the peril of his own position. The glass room! What on earth was the fellow talking about? And what did it all mean? What were the sights which would give a man bad dreams for a month?

Just then Tim nudged him. "They didn't see us, anyway," whispered the Irish boy. "Be watching now. We'll be starting in a minnit."

Mr Trench, however, made no move. He remained where he was, crouching behind the tall stalks of tasselled corn, until the two men had laid their coils of wire down and actually got to work. Then he touched Cyril on the shoulder.

"Now's our chance," he said in a low voice. "Follow me. I needn't tell you to go quietly."

Bent double, he stole away in the direction of the pillared entrance, and soon gained the western end of the front of the building. Then he turned sharp to the right, and, like shadows, the three stole along under the enormously massive wall.

There were no windows or openings of any sort in the tremendous wall. As Cyril passed along he was impressed by the gigantic size of the stones of which it was built. Some of them seemed to be at least twenty feet long.

Cyril's heart was pounding. At last they were almost within reach of Stella. He felt certain that she was held prisoner in this strange old building. Yet, close as they were to her, it was quite impossible to tell whether they could rescue her.

Neither Trench nor he had any idea how many of Kent's men there were inside. There might be a dozen, for all they knew, in which case the chances were that they themselves would be prisoners like Stella before many minutes were over.

Yet he was not conscious of any fear, only of a tingling excitement.

Mr Trench reached the pillar guarding the left-hand side of the entrance, and came to a stop in its shadow. It was a tremendous affair, fully ten feet through, and seemingly cut out of a single block of stone.

Now came the ticklish part of the business. The searchlight glowed out from an opening exactly over the entrance, and to get inside the three would have to pass right under it.

Mr Trench put his mouth close to Cyril's ear.

"I will go first," he said; "you follow, then Tim."

Cyril nodded, and next instant his leader had swung round the great pillar and vanished.

Cyril paused a moment. There was no sound. He beckoned to Tim, and followed. Tim came close after, and in a moment they were both inside, and standing beside Mr Trench, in an immense pillared hall.

The floor was paved with gigantic flags of smooth stone, and the roof was also of stone, but painted with all sorts of strange figures, mostly animals. Rows of vast pillars supported the roof, and the whole of the ancient place was lit by modern electric lamps dangling from the roof. It was the oddest contrast that Cyril had ever seen.

Mr Trench stood perfectly still, listening. But there was no voice or movement. The only sound was the low hum of an unseen dynamo.

"All right so far," said Mr Trench in a whisper. "The next thing is to close the door and make it fast. As you see, our friend has not spared trouble to make a good job of his doors."

It was true. A great pair of folding doors had been set in place. They were quite rough, being made of planks sawn from the felled trees, but they were certainly stout. Also, they were provided with great bolts and a chain.

"Won't the men out there see us closing them?" asked Cyril.

"Possibly. But what does it matter? They won't be able to get in. There is no other entrance on this side. Still, we may as well go about it as quietly as we can."

Cyril nodded, and they pushed the doors to. The hinges seemed well oiled, for they moved quietly enough. And as there was no sound from outside it seemed that the men did not notice what was being done. They dropped the bolts into the staples and made all fast.

"It's meself would like to see ould Kent's face whin he finds himself barred out of his own residence," Tim remarked. "Wouldn't we go and shut the other door now, sorr?"

"Not yet. First, we must tackle this man who is running the searchlight. We must handle the men one by one, or we don't know what we may be running our heads into. The question is, how are we to get at him?"

"Up that ladder," replied the quick-witted Tim, pointing to a rough wooden ladder which ran up to an opening in the roof.

Mr Trench nodded approvingly.

"Yes, that's the way without a doubt. Go quietly. We must take him unawares. We don't want any shooting if we can help it."

He led the way to the ladder. Cyril followed with a queer sense of unreality, a sort of feeling that he must be in a dream.

As he crossed the hall he noticed that the floor sloped at quite a steep angle toward the lake. Yet the huge flags had been so perfectly cemented that there was no crack anywhere. The whole building had tilted like one stone.

The opening through which the ladder ran must have meant a lot of hard work to cut, for the upper floor was as solid as the lower. As he put his head up he was aware that this upper storey was nearly dark. There was just one electric bulb, and that over the head of the man who was working the searchlight. As for the searchlight itself, its whole ray was reflected outward through an arched opening.

Cyril crouched breathless at the top of the ladder. So softly had the three come up that the man had not heard them. He sat, idly watching the pair who were stringing the wire outside.

Mr Trench signed to the boys to stay where they were, and crept softly forward. Cyril saw that he had his automatic ready in his hand.

Cyril's eyes were fixed upon the searchlight man. He was not very young and rather stout. He had red hair and a ginger moustache, and was a big, powerful fellow.

Moving with that absolute silence that only a big-game hunter or an Indian ever attains, Mr Trench made a half-circle, and came up behind him.

"Hands up!" he said suddenly.

With his hands above his head, the man turned slowly round, and as his eyes rested upon Mr Trench, they were filled not so much with fright as with amazement.

"Glory!" he said. "If it ain't Mr Trench!"

Mr Trench looked equally surprised.

"You, Gregor!" he exclaimed.

"It's Gregor all right, sir. But how you come here beats me."

"I have been here in the valley for some months," replied the other, "but I confess I did not expect to see you in this rogues' gallery."

"If I'd known what it was, sir, I wouldn't ever have come," was the reply. Then a scared expression crossed his face. "But, see here, sir," he went on, "if the boss comes you're in for it. You don't know what you've run your head into."

"On the contrary, I know very well," replied Mr Trench coolly. "But tell me one thing. Are you on my side or Kent's?"

"Yours, sir," answered Gregor unhesitatingly. "I'd give a year's pay to be out o' this. Do you reckon you can get us away?"

"I do—with your help. First, is there any other entrance to this place except the one just under us?"

"Not on the land side, sir."

"That's all right. We have bolted the door."

"Then there's more than you, Mr Trench?"

"Two boys—smart ones, too. They are here to rescue the girl, Stella Earle, from Kent's clutches."

"About time, too, sir. It's a shame and a scandal the way Kent treats the child. And she plucky as they make 'em."

He broke off, and chuckled.

"So you've locked Jonas and Mark outside, sir? A pretty row there'll be when they find out."

"So long as they can't get in, that doesn't matter. What I want to know is, how many men are there in the place besides you?"

"Only two, sir. Bleak as runs the dynamo, and the Chink who does the cooking. Chin Su they call him."

"Will they give trouble?"

"Not with the odds against 'em, as they are," was the prompt reply.

"And how many in the airship with Kent?"

"Eight—and a tough lot they are."

"Do you know where he has gone?"

"Just scouting, I reckon. He's always got the idea that some one will be after him. Guilty conscience, I expect."

"He hasn't heard of the other airship?"

"Not that I know of. But if he had, he wouldn't say. He's a close one, is Kent."

Mr Trench paused a moment, thinking. Then he spoke again.

"We must secure Bleak and the Chinaman first," he said. "Then we must get hold of the little girl. Where is she, Gregor?"

"In the glass room, I'm afeared, sir. Kent, he puts her in there just to get the better of it. But do what he will, she won't be civil to him."

Cyril hurried forward.

"What is this glass room?" he demanded. "I heard one of the men outside speak of it. It must be something perfectly beastly."

Gregor looked at him.

"You can take your oath on that," he answered grimly.


CHAPTER XX
THE GLASS-FRONTED ROOM

CYRIL caught hold of Mr Trench's arm. "We must get her out at once." His usual calm had failed him, he was trembling.

"Steady, my lad," Mr Trench answered, and his usually harsh voice was extraordinarily gentle. "We cannot afford to take chances. We must settle with Bleak and the Chinaman before we do anything else. With Gregor here to help us it won't take long."

"The little girl won't take no harm for just a few minutes longer, sir," said Gregor. "I'd better leave the searchlight on, hadn't I, Mr Trench?"

"Much better." As he spoke the big man glanced at the opening through which the beam was directed. "No, that's not big enough for them to get through," he said, "even if they had a ladder."

"Which they ain't, sir," said Gregor, and rose.

"Now for Bleak," he said. "And I'll tell you, Mr Trench, there isn't nothing will please me better than to get square with that swab. He's one o' Kent's kind. I can't size him up better'n that."

Gregor grinned as he started towards the ladder-head. It was sufficiently plain that he had scores of his own to settle with the man Bleak.

Presently all four were back in the great hall where the brand-new electric lamps flung their hard glitter on the dim pictures of a forgotten civilization.

"This way, sir," Gregor said, leading them across the sloping floor to the eastern side of the hall.

Here a large portion of the ancient building had been partitioned off, forming different rooms.

"This here's the dormitory for us men," said Gregor in a low voice. "Next is Kent's room, but that's locked. Then there's the kitchen, and, last of all, the engine-room. Go quiet. I see as Bleak's got the door open."

He paused. "I'll go first, sir," he said. "He won't think anything of it if he sees me."

He chuckled silently, and passed on to the door from which came a hot glare of light, a strong reek of oil, and the deep-toned hum of a powerful dynamo.

Mr Trench motioned the boys to keep back, and took his stand just outside the door.

"What's up with you, Gregor? What do you want here?" came a hard, hostile voice from within.

"You got too big a load on, Bleak," answered Gregor. "That's what I come to tell you. You'll be fusing the plugs next thing, you know. I told you of it before."

Bleak swore savagely. "You got the cheek to talk to me like that! Think you knows more'n me, I suppose. Take your ugly face out o' this, or I'll make it so your mother wouldn't know it."

There was the sound of hasty steps on the stone floor. Then with his uncanny quickness Mr Trench was inside, and "Hands up!" came his quick, sharp order.

Cyril stepped in behind, and Tim followed. There stood Bleak, a huge fellow with the chest and arms of a gorilla and a great hairy face. But his long arms were above his head, and he was helpless.

"Bit of a surprise for you, eh, Bleak?" jeered Ben Gregor. "But keep them hands up, or there'll likely be an accident. This gent's the best shot in Africa, bar none."

"You dirty traitor!" bellowed Bleak, in a passion of rage. "I'll see you fed to them eels in the lake afore I'm a day older. Aye, and you, too, you fellow with the gun."

"That will do," said Mr Trench sharply. "Tie him up, Ben, and make a good job of it."

Gregor did the tying with all a sailor's skill and swiftness, and with evident pleasure. Cyril breathed more freely once he realized that this formidable brute was at last helpless.

Having deposited Bleak on the floor in a corner, Gregor proceeded to cut out the dynamo. "There's plenty o' juice left to carry on," he said. "This here's only for the searchlight, and it don't make no odds if she goes out. Now we'll see to the Chink, but he won't give no trouble. One master's as good as another to a chap like him."

They found Chin Su busy over a neatly black-leaded stove in a kitchen which was as modern and tidy as if it belonged to a suburban villa. As Ben had prophesied, there was no need for violent methods.

"This gent's your new boss, Chin. Savvy?" said Ben. "He'll be an easier one than Kent, and pay your wages just the same, so there's no call for you to worry."

There may have been some faint shade of surprise in Chin Su's almond eyes as they rested on Mr Trench. But, if so, the look was gone as soon as it had come.

"Me savvy," said the Chinaman; and bent again to his cooking.

"Some cook he is, too," observed Ben; but Cyril cut him short.

"Stella," he said. "We must find her now."

"That's so," agreed Ben. "Come right along. I'll show you."

As they crossed the great hall suddenly shouts sounded outside.

"That's Mark and Jonas," observed Ben coolly. "Most like the searchlight's gone out on 'em."

Aware that the two ruffians were quite helpless, the others did not bother their heads about them, but hurried after Ben down the sloping floor toward the lake side of the vast building.

"Tipsy sort o' place, ain't it, sir?" observed Ben. "When I first came here I always had a nasty feeling as if it was all a-going to slide into that great pit of a lake. But I got over that now. I reckon it's been like this for maybe a hundred years past."

"A thousand for all we know," answered Mr Trench. "There is no sign of any recent slip. Is this the way down?"

Ben had stopped at a large square opening in the floor. By the light overhead they saw a flight of massive stone steps leading down into the depths beneath.

"Yes, sir. What they calls the glass room is down below here. No, there ain't no need for a light. Kent's had the whole place fitted with electric. Looks to me like he means to stay here for always."

"Does he?" said Mr Trench grimly, and stalked away down the steps.

Beneath was a passage—a wide gallery floored and roofed with cyclopean slabs. On either side were square openings into great underground chambers which, perhaps, in the old days had been granaries or treasuries. But there was no time to explore these now. Ben led straight on down the passage, which, like the floor above, sloped toward the lake.

At the end they came to a door—a rough, but solid, door of sawn planks.

"This here is the glass room," said Ben, as he pulled back the heavy bolt which fastened it.

Mr Trench pushed Cyril forward.

"You go first," he said. "She knows you."

And Cyril, with his heart fairly thumping, went quietly forward into a large stone chamber. The great bare place was brilliant with electric light, which showed every chisel-mark on the ancient stones.

For a moment Cyril stood quite still. The first thing he saw was that a part of the wall opposite to the door had been replaced with glass—glass of immense thickness. The strong light shining through it showed beyond it the clear green waters of the mysterious lake. The whole place was beneath the level of the lake, and the window was like a ship's scuttle, an immense circular porthole.

All this Cyril took in at a glance, but without really thinking of it. The next instant his eyes were fixed on a small, hard-looking little bed which stood opposite to the porthole. It was clamped to the floor, so that it could not be moved. And in the bed, its head covered with a sheet, lay a slim little figure. There was a powerful electric lamp almost over the bed, tilted so that its rays fell full on the green glass of the porthole.

Cyril stepped forward quickly; then stopped. There was no movement from the bed. It was Stella, of course; but was she alive? Why did she lie so dreadfully still?

"Stella!" he said, and his voice was curiously weak and hoarse. "Stella!"

Now the figure on the bed did move. Very slowly the sheet was pushed back by two small hands which were sadly thin and white. A mass of fair hair became visible, and then—then Stella's face.

At sight of Cyril her hands dropped, her blue eyes opened wide; but she lay still as if frozen, staring in utter silence.

"Stella!" said Cyril again. "Stella, it's Cyril! Don't you know me?"

Still she stared.

"No. I've seen you before, and it wasn't you," she said, in a thin, sad little voice. "It's just another dream."

Cyril came forward.

"I'll soon show you if it's a dream, Stella," he said; and, stooping over her, flung his arms round her and kissed her.

She gasped.

"It's you! It's really you at last! Oh, Cyril!"

She burst into tears, and Cyril held her tight and stroked her hair.

Presently her sobs ceased. She stiffened.

"Where is Kent?" she demanded.

"Gone off in his airship. Don't you worry about him, Stella. He shan't hurt you any more. Tim's here with me, and Mr Trench, a friend of ours, and Ben Gregor. You're quite safe."

"And Uncle, is he here?"

"Not far off. We have a big airship—a bigger one than Kent's. Now dress yourself, dear, and come up out of this."

"I am dressed, Cyril. I never dared take my things off here. Somehow I always felt they would get in sooner or later."

"Who—what are you talking about?"

Stella shivered again and pointed. Cyril, following the direction of her pointing finger, looked towards the scuttle. He started and stood staring.

"Ugh!" he muttered.

The sight was enough to make anyone quake. Exactly opposite the scuttle, and with its nose close against it, was a creature so horrible that it hardly seemed possible it could belong to earth. It was eel-like in shape, quite fifteen feet in length and of a brilliant green colour. Its head was long and pointed, and its mouth armed with rows of white teeth looking sharp as needles.

All down its back ran a fringe of fin spined like that of a cat-fish, but its eyes—they were the dreadful part of it. Long, narrow, and black as jet, they had a look of cold and deadly malice impossible to describe.

"What a brute!" gasped Cyril. "And—and there's another!"

"There are heaps of them!" said Stella, still clinging to him.

"And Kent leaves you alone here!" exclaimed Cyril; and Stella had never before heard that tone in his voice.

It was like a man's voice, cold and deadly.

Without another word, he picked her up bodily. Stella had always been a slim little thing; now she was painfully thin, and Cyril carried her with hardly an effort. Holding her in his arms like a baby, he marched straight out of the place, right up the passage and up the stairs. The others followed him in silence.

At the top he turned to them.

"You saw it?" he asked.

"I did that," Tim answered; and his small face was as set as Cyril's own. "Sure, a man that can do a thing like that shall have no mercy from you or me, Cyril."

"No; I don't think we shall be too tender with the gentleman once we catch him," said Mr Trench drily. "But for the present the thing is to get out of this. Gregor, how are we to do it?"

"If there's a boat at the water-gate we can take that," Gregor answered. "I'll go and see."

He started and the others followed.

The hall was of enormous extent. It was quite a long walk through the forest of columns supporting the roof before they reached the wall next the lake. Here was another great square doorway similar to the one in front, but, owing to the strange tilting of the whole building, the floor of this was under water, and the water filled all the lower end of the hall.

A rough, but strongly-built, pier spanned the deep, still pool and reached the entrance.

Gregor pulled up short.

"No luck, sir," he said to Mr Trench. "Both the boats are away. They're over by the float."


CHAPTER XXI
JUST TOO LATE

GREGOR was right. Both the boats were lying moored alongside the big float on which Kent kept his airship.

Mr Trench stood silent, tugging at his beard and frowning.

"If it weren't for those eels," he muttered half-aloud, "I'd swim for them."

"And what for would ye be swimming, sorr?" broke in Tim quickly. "Why shouldn't we build a raft and fetch them?"

Mr Trench smiled grimly.

"I suppose because it takes an Irish boy to think of these things. But you're right, of course, Tim. Gregor, is there stuff in the place?"

"Any amount, sir. Come, and I'll show you."

He led the way to a store close to the dynamo-room, where the big ruffian Bleak was still imprisoned. Here were piled heaps of rough-sawn planks.

"Enough to build a ship," said Cyril, as he plunged in and began sorting out the stuff.

"That's right, Cyril," said Mr Trench, as he followed Cyril's example. "Now then, pitch in, all of you! Remember we are working against time. Kent may be back at any minute, and we must be well away before he arrives."

The rest needed no urging. They set to work with tremendous energy, dragging the planks clattering across the great sloping stretch of flagged floor down to the water-gate. Even Stella wanted to help, but that Cyril flatly forbade. He made her sit down comfortably on a pile of blankets and watch.

The wood was new and green, and consequently very heavy. This meant that it floated badly, and Gregor, who knew something about the beasts that lived in the lake, insisted that they must have something to keep them well above the water. So the raft, only meant for one, had to be heavier and bigger than they had at first intended.

The consequence was that it took longer to build than they had expected, and when it was done they were all startled to find that it was nearly half-past four. Dawn would be on them in an hour.

Mr Trench was in the act of stepping on the raft when Gregor stopped him.

"No, sir," he said firmly. "Begging your pardon, it's me that's going."

"Why?" demanded Mr Trench half angrily.

"Because you can shoot, and I can't, sir," replied Gregor drily.

Mr Trench merely nodded.

"I understand. Good luck to you, Gregor."

Gregor picked up the paddle and pushed off. By his directions Tim had brought a powerful electric lamp from the store-room, and stood at the water-gate, keeping the light full on the raft. Beside him Mr Trench took his stand, rifle in hand.

The heavy raft moved slowly across the glassy surface toward the float, while the rest watched in anxious silence.

Suddenly Cyril stiffened.

"What's that?" he asked, pointing to a spot close to the raft, where the water bubbled oddly.

Next instant the surface broke, and a head resembling that of a monstrous pike rose above the surface. But it was bigger far than that of any pike that ever lived, and seemed to be made of solid bone. Its eyes, as large as twin saucers, glowed hideously in the light of Tim's lamp.

Its dart at the raft and the roar of Mr Trench's .450 were simultaneous.

"Ye got him, sorr!" yelled Tim in high delight.

"Hit him, anyhow," replied the big man quietly, as he watched the water boil where the unknown monster lashed in a death struggle among the foam.

Waves washed right over the raft, but Gregor never once stopped paddling. He kept steadily on.

Nothing else attacked him, but the watchers sighed with relief when they saw him reach the float and spring safely upon it. Leaving his raft, he at once jumped into the larger of the two boats. Then he untied the smaller, fastened it astern, and, shipping the oars, pulled back to the others.

"I thought likely I'd need your rifle, sir," he said, as the boat touched the floor of the inner pool.

"You did quite right to bring both boats," said Mr Trench. "Now get aboard, all of you. Put Stella in the stern. We must be well away before dawn."

At that moment Tim, whose ears were sharper even than Cyril's, stiffened suddenly, and held up his hand for silence.

"I'm afeard it's too late, sorr," he said gravely. "'Tis Kent I hear coming back."

All waited in deathly silence. They hardly breathed. Then through the still, cool air all were able to hear a faint, distant humming like that of a swarm of bees.

Mr Trench drew a long breath.

"You are right. Perhaps it's just as well we did not start."

The humming grew rapidly louder. The quiet air throbbed with the vibration of the powerful engines.

"Good thing I brought both boats," said Gregor grimly. "They can't get at us so very easy now."

"We'd best close the water-port all the same," replied Mr Trench; and this was done at once.

"Will he bomb us, Gregor?" continued Mr Trench.

"I don't know what villainy he'll be up to, and that's a fact," answered Gregor; "but he has guns and bombs with him. If I was you, sir, I wouldn't let him land at all."

"How can I help it?"

"With that big rifle of yours, sir. Wait till he gets low enough; then let him have it."

"Why not wait till he is on the float?"

"Because then he can work his machine-guns on the port, and none of us will be able to live near it."

"I understand. Cyril, take Stella back into safety. Gregor, open the door wide enough for me to shoot. I've a notion that Kent is going to get the surprise of his misspent life."

The roar of Kent's engines grew till it was almost deafening; then ceased so suddenly that, by contrast, the stillness seemed uncanny. The dirigible came sinking down slowly and steadily toward the pontoon. The dawn was just beginning to dull the stars, and the airship bulked monstrous in the faint grey light.

Mr Trench waited calmly until she was within easy range; then raised his rifle to his shoulder, and, aiming at the central gondola, began to fire.

As the echoes of the first shot went rolling and thundering out across the lake, a yell of terror or pain rang out from the airship. Then all heard Kent's harsh voice barking out orders, and almost instantly a machine-gun answered.

"Look out, sir!" begged Gregor.

But the big-game hunter paid no attention. He kept on firing steadily, and every shot told. The big bullets raked the huge target from end to end.

Whether he was doing much damage or not, it was impossible to say; but, at any rate, Kent's men were badly rattled, for their shooting was all over the place. The lake was lashed with showers of lead, but not a shot came into the water-port.

"They're rising!" cried Tim.

Sure enough, Kent had had enough of it. Water ballast streamed out, and the airship shot up rapidly out of range.

"Now, I suppose, he'll bomb us," said Mr Trench quietly.

"Not likely," replied Gregor. "He won't burst up his own property."

"Then what can he do?"

"He'll do something, sir; never fear. But he won't bomb the palace just yet."

There was a long pause. As a matter of precaution, Stella was placed in safety in an underground chamber. Cyril was ordered to stay with her. The others waited breathlessly. They could hear the airship maneuvering at no great height overhead.

Presently came a splitting crash and a flash of vivid light. The whole building quivered.

"'Tis in the front!" cried Tim. "What's he afther? Wait now; I'll go and see."

As he dashed up the ladder to the searchlight-opening there were yells of terror from outside.

"That's Jonas and Mark!" chuckled Gregor. "They don't like it."

"I don't blame them," said Mr Trench. "But what on earth is Kent about?"

Another crash. Tim came flying down.

"'Tis the wire fence he's bombed, Misther Trench! Sure, it's all bust up!"

"The fence," repeated Mr Trench, frowning. "Ah, I have it! He means to let the Karaleks in upon us."

Tim whistled ruefully.

"It's the cunning rascal he is, sorr! I'm thinking you're right. But how will he get at thim?"

"Drop a man in a parachute, most likely. Let's go and look. It's safe enough for the present."

They went up to the opening. Dawn was rosy on the rock rim to the east, and a heavenly morning was dawning. Outside, the fence lay in ruins. Two small bombs, charged with high explosive, had shattered posts and wire, and dug great red pits in the ground. The airship herself was about half a mile away, hanging motionless in the still air at a height of, perhaps, two thousand feet. Even as they watched, they saw a man climbing over the edge of the central gondola.

"What did I tell you?" said Mr Trench; and, as he spoke, the man leapt clear.

For the first couple of hundred feet he dropped like a bullet; then the ball of the parachute opened out, and he went swaying gently downward, drifting away from them.

Mr Trench whipped his field-glasses out of their case and swiftly focused them.

"Phew!" he muttered. "It's Kent himself. The man's a blackguard, but he has certainly got pluck."

Kent disappeared behind the trees. The airship dropped slowly, and presently lowered a grapnel and was moored. Mr Trench shut his glasses with a snap.

"What shall we do, Gregor? Slip out the back way and trust to escaping unseen by boat, or stay and fight?"

Gregor shrugged his broad shoulders.

"They'd be sure to spot us if we hooked it. I say, stick it out!"

"And so do I, sorr!" said Tim firmly.

Mr Trench nodded.

"I think the same, and I feel sure Cyril Hamer would agree. See here; we have a good hour before us. Tim, go and tell Chin Su to give us some breakfast. Gregor, you and I will attend to the defences. Are there any more rifles in the place?"

"Plenty, sir; but they are locked in the armoury."

"Then let's burst the place and get them out. This is going to be a tight fit, Gregor," he went on, in a lower tone. "There may be a hundred or more of these niggers, and, mind you, they can fight. We shall have our work cut out to keep them off."

"You can't tell me anything about them," responded Gregor. "I've seen 'em. All right, sir, let's get the guns."

The armoury door was two inches thick, yet it did not keep Mr Trench and Gregor out for very long. They got out the best of the rifles and plenty of cartridges, and by the time they had done that the Chink had breakfast ready.

He was a great cook, and there were hot rolls, venison chops, and excellent coffee with preserved milk.

Watch was kept by one of the party at the porthole over the great central door while the rest ate. They took guard in turns, and Tim was the last to go up. The sun was well up now, and the beautiful forest and lake were bathed in brilliant light.

Cyril was just finishing his second cup of coffee, which Stella had poured out, when there came a shout from Tim.

"Here they are! They're coming, and 'tis not a hundred they are, but more like three!"


CHAPTER XXII
THE PURPLE CLOUD

INSTANTLY Mr Trench took charge, and his orders were rapped out clear and sharp.

"Put Stella in the kitchen with Chin Su. That's the safest place. Cyril, you come with me. You too, Gregor. Tim, you can stay below and fire through the loophole in the big door."

Rifle in hand and his pockets bulging with cartridges, Cyril raced up the ladder behind his leader, and Gregor, similarly loaded, followed.

"Here they come!" said Mr Trench between his teeth. "Aim low, Cyril. Remember, we must stop them from reaching the main door."

The Karaleks came charging in a mass through the gapped fence. In the blazing morning sunshine they looked more like demons than men, and from their fierce faces and savage yells, it was plain that they were worked up to the highest pitch of fury.

Mr Trench waited until the nearest were within about fifty yards, then, "Fire!" he snapped out sharply.

All three rifles spoke at once, and from below came the crack! crack! of Tim's weapon, as he blazed away through the loop-holed door. The rifles were Winchester repeaters, firing a heavy .44 bullet, and at such close range, and with such a big target, it was impossible to miss.

The cannibals were bowled over in dozens.

But it would have taken a machine-gun to stop them, they were so many, and though the garden in front was strewn with their black bodies, most of them reached the great porch.

And now Cyril saw that the van carried a great tree-trunk. This they used as a battering-ram, and the crash as its heavy end struck the big doors boomed like a drum through the echoing halls.

"That's bad," muttered Mr Trench, as he leaned forward, trying to fire directly down upon the men who held the ram.

With a clang a great spear, headed with native iron sharp as a razor, struck the wall immediately above his head, and Gregor seizing him, dragged him back.

"Look out, sir. If they get you, we're done. You let me do that job."

Thrusting himself forward he began blazing away as fast as he could pull trigger, and so fast and accurate was his shooting that the Karaleks fell back, dropping their log.

"That's fixed 'em," exclaimed Gregor, and next moment back he stumbled and fell upon the stone flooring. A spear had caught him in the left shoulder and had sliced through the flesh like a carving-knife.

"It's all right," he gasped struggling up again, but Mr Trench dropped his own rifle and snatched out a first-aid case.

"Go on shooting, Cyril!" he ordered. "Gregor, you wait till I've tied up that wound."

Cyril was already in Gregor's place and firing fast. Down below Tim's rifle rattled steadily.

But the Karaleks, though losing terribly, seemed to be wound up to a sort of Dervish fury. A dozen more springing in lifted the log again, and came charging furiously at the door.

This time the crash of the impact was followed by an ominous splintering sound. Tim however still kept up a tremendous fusillade, and with Cyril's help succeeded in keeping the cannibals back—at any rate for the moment.

The heat was frightful, and the perspiration pouring down Cyril's forehead into his eyes, nearly blinded him. His throat was dry, and as for his rifle barrel it was too hot to touch.

He heard Mr Trench's voice in his ear. "Gregor's badly hurt. He'll do no more shooting to-day. And a lot of those beggars are close under the porch where we can't reach them. Cyril, you go down the ladder and help Tim. I'm going to carry Gregor down."

"Do you mean you're going to clear out, sir?" asked Cyril.

"That's it. I'd rather chance Kent than his cannibals. Besides we've a better chance than—"

His voice was drowned by a fresh crash below, as for a third time the ram came crashing against the door. Cyril waited no longer, but fairly leaped down the ladder.

"They've got us cowld," Tim gasped as Cyril joined him. Tim's face was black with powder, smoke and dirt. His voice was a hoarse croak.

"It's all right. We're going to clear out in the boat. But don't stop shooting. Keep 'em off at any price while Mr Trench takes Gregor to the boat. Gregor's hurt."

A moment later, Mr Trench was with them. He was supporting Gregor who, in spite of his pluck, was almost helpless. An artery had been cut through, and though Mr Trench had patched him up, he had lost a lot of blood.

"Keep it up, boys," said Mr Trench. "I'll get Stella, and when you hear my whistle, come running for all you're worth."

He was gone, and the two boys, left alone, kept up a hot fire through the loophole. They took it by turns, each stepping aside as he emptied his magazine and giving way to the other.

But the Karaleks, having learnt by bitter experience, were now too cunning to come up in front of the loophole. They had shifted the battering-ram, and were attacking the left side of the door. At the fifth blow the upper hinges gave way, and that leaf of the door began to sag. If it had not been excellently constructed it must have gone down.

"The next blow'll do it," muttered Tim, as he rammed a fresh clip of cartridges into his magazine.

He had hardly spoken before there came the shrilling of a whistle from the far end of the great hall. Tim thrust his rifle out, fired the whole magazine-full as quickly as he could pull trigger, then he and Cyril bolted as hard as they could go down the long slope of the floor.

The boat was ready, Stella in the stern-sheets, and Gregor lying on cushions in the bottom. Cyril saw too that there was a keg of water and a case of provisions. Chin Su was not there, but there was no time to ask about him.

"In you get," snapped Mr Trench.

The speed with which the party embarked was wonderful, but they were hardly in the boat before a terrific splintering sound from above was followed by a burst of fiendish yells.

"The door's down. Pull!" cried Mr Trench.

He took one pair of oars, Cyril and Tim shared the other, and the boat shot out on to the glassy surface of the lake.

"Keep round to the left, under the bank," ordered Mr Trench. "The bulk of the building will hide us, and once we are round the point the Karaleks can't see us."

There was no need for urging. Already they could hear the patter of the feet of the savages, as they came racing down the slope of the great hall. Stella, plucky as any of the crew, steered, while the other three pulled till the veins stood out on their bare brown arms.

A blood-curdling yell rang out as the savages realized that they were balked of their prey. At the water-port appeared a score of gruesomely hideous faces contorted with rage and disappointment. Some flung their spears, but the boat had already passed the mooring-stage, and was well out of range.

For a few moments the mob of furies stood mopping and mowing, brandishing their weapons, and uttering hideous cries. Then with one accord they turned and disappeared.

"Wonder what they're after now," was Cyril's unspoken thought.

As if he had uttered the question aloud, Mr Trench answered it. "They're going to hunt us along the shore," he said. "Keep a little out Stella."

Stella who, though pale, was amazingly calm, obeyed quietly, and the boat drove along just out of spear-range from the shore and, heading westward, down the lake.

The water was like molten glass, and the sun blazed down with intolerable fury. Cyril felt as if his brain was boiling, while his tongue stuck to the roof of his mouth. Though he pulled as hard as ever, yet his spirits were at a very low ebb.

It was true that they had escaped the Karaleks, but what was the use of that when they were at the mercy of Kent? He glanced back at the long slim shape of Kent's airship where she hung poised against the intense blue above the lush green of the forest. Her grapnel was still down, and she hovered almost motionless in the still and sultry air. Kent had not moved yet, but he would soon. Cyril felt certain that the ruffian's eyes were on them. He was playing with them as a cat does with a mouse.

Again Mr Trench seemed to guess his thoughts.

"Look to the north, Cyril," he said in a low voice.

Cyril looked, and became aware that, above the rim of the mountain opposite, the air had lost its translucent clearness. A haze had covered the jagged-rock rim, a haze which thickened even as he watched it, and the heart of which darkened rapidly.

"Rain?" he asked.

"Rain—and wind—and a few other things," answered the big man grimly. "If Kent isn't quick he'll lose his chance."

"Sure, he sees it," said Tim, speaking for the first time since they had left the temple.

Tim was right. The crew of the airship were busy. Not waiting to release their grapnel-rope, they had cast it loose. The low roar of her engines broke the sultry stillness, and she began to swing round with her head in a westerly direction.

Cyril gasped. To him it seemed that now all was really lost, for the storm on which Mr Trench appeared to be depending was still a good way off, and it did not look as if there was any chance of its breaking in time to save them.

Still pulling hard, they rounded a tree-clad point, beyond which was another small bay. Here a stream coming down the great slopes above ran into the lake. Its mouth was almost hidden by a forest of gigantic reeds.

"In there, Stella," said Mr Trench, "close in."

Cyril was horrified. He thought that Mr Trench must have taken leave of his senses, for if they approached the shore they would be again in reach of the throwing spears of the Karaleks. But Stella obeyed unhesitatingly, and the boat was run into the thickest of the reeds, close to the mouth of the brook.

These reeds were the papyrus of the Nile, but enormously bigger. In this rich, hot valley they had grown to a height of twelve or fourteen feet, their stems were nearly as thick as a man's wrist, and they were as dense as a hedge.

"Pull hard!" snapped Mr Trench as the boat neared the edge of the reed forest, and as he spoke he dug his oars in with all his might. The boat crashed into the reeds, driving in her full length and remained firm there.

Mr Trench shipped his sculls and wiped the perspiration from his streaming forehead. "We're safe here for a bit at any rate," he said. "Pull the reeds down over her, boys. Yes, that's right."

"But how can we be safe?" inquired Cyril anxiously. "The Karaleks are all down the edge of the lake."

Mr Trench smiled—actually smiled.

"Look about you, Cyril," he said, and pointed significantly to the shore.

Cyril looked, and presently understood. "Mud!" he said in a whisper.

"Yes, mud. It's bottomless and soft as soup. Even the alligators shy at it. We're safe enough from the niggers so long as we stick here."

"But Kent?" said Cyril. "He's coming nearer. Can't you hear her engines?"

"I know. But he can't see us—and by the time he finds us—"

He paused, and pointed significantly to the cloud.

Even in these few minutes this had thickened to a real storm-cloud, a dense mass of purple vapour, with a rim white as fleece, which rolled over and over in a strange and rather terrifying manner. "You take my word for it. Kent isn't going to risk getting caught in that."

"But we are," was on the tip of Cyril's tongue yet he did not speak the words. It was no use frightening Stella. Then before anyone could speak again a white flash lit the heart of the great cloud, and rolling heavily across the placid lake came the sullen boom of thunder.

It died, and the utter silence was broken only by the continuous roar of Kent's engines.

"He's still coming," ventured Cyril.

"But he won't come this far," answered their leader with a calm confidence which was very helpful. "You wait."

Wait they did in silence. Covered up as they were and hidden in the thicket, they could not see the airship, but only hear her engines, and so close was she that it was not difficult for Cyril at least to tell almost exactly what she was doing.

Presently he looked at Mr Trench. "She's coming down," he said.

"She is that," added Tim. "Ah, there she's stopped. She's dhropping."

Again the lightning flashed and the thunder boomed. When the sound ceased all was utterly still.

"What did I tell you?" said Mr Trench. "She's down on her float, and I'll lay my rifle to a cartridge Kent is sweating his men to get her snug before the storm breaks."

"It won't be long now," said Cyril.

Mr Trench nodded. "And it mustn't catch us here," he said with decision. "There'll be a sea that would fill us in five minutes and sink us so deep in this mud, we'd never get out again."

Tim started up. "It's right ye are, sorr. I was thinking that same meself. But where will we go?"

"Get her off the mud, and I'll show you," answered Mr Trench, as he began to push with an oar.

It took them the best part of five minutes to get the boat off the sticky mud, and by that time, the whole of the northern sky was black with cloud, in the heart of which lightnings of many colours flickered wickedly.

"Which way, sir?" asked Cyril, setting to his oar.

"West, down the lake, and if you value your life you'll pull as you never pulled before," was the answer.


CHAPTER XXIII
THE STORM BREAKS

THE dead hush which precedes a storm brooded over the crater-valley as they pulled away out of the rushes. The monstrous cloud had cut off the sun, and a darkness like midnight was broken only by a constant flash and flicker of lightning. The air was so thick that Cyril felt he could hardly breathe, and the heat was that of a Turkish bath.

Driven by her two pairs of oars, the boat travelled fast through the quiet water, but Cyril at least had no idea for what point they were making, or what their leader had in his mind.

Suddenly round the point which they had passed a second boat shot into view. It was being pulled by four men.

Cyril drew a quick breath, but said nothing. It was Tim who spoke.

"It's crazy we were," he muttered bitterly. "We'd ought to have sunk her."

It was true, but in their hurry to escape the Karaleks they had forgotten to put the second boat out of commission. Now, it was clear, they were to pay for their forgetfulness. If Kent could not chase them in his airship, he could in the boat, and with four strong men pulling, it was only too clear that escape was out of the question, for Kent's boat was travelling nearly three feet to their two.

"Will we stop and fight thim?" panted Tim straining still at his oar.

"No. Carry on," was the curt answer.

Carry on they did, while every moment the darkness increased, and the lightnings flashed more fiercely. The thunder shook the sullen air.

"Closer in, Stella," said Mr Trench presently. "Round that next point of rock."

Stella nodded and turned the boat slightly. Glancing back over his shoulder, Cyril saw that they were heading for a rocky promontory which rose out of the water about a quarter of a mile beyond the mouth of the brook.

A dull roar came to his ears. It was not thunder, but a steady sustained note which, instead of rolling and booming like thunder, grew louder rapidly, like a train approaching out of the distance.

"She's coming," said Mr Trench, behind him.

Cyril knew. It was the wind, and already the far end of the lake was blotted out by a dark mist which swept toward them at frightful speed.

It was edged by a line of white which came rushing across the surface of the water. It was not only wind, it was a hurricane, and for the moment Cyril forgot all about their pursuers, and pulled with frantic and desperate energy. He realized that their only chance of life was to get beyond that rocky point before the storm caught them.

Kent's men knew it, too, for quite suddenly they abandoned the pursuit and began to row furiously for the shore.

Now it was nip and tuck. The boat was quite close to the point, but that seething edge of foam was only a few hundred yards away, and coming up with appalling speed.

"Keep in—close in, Stella!" ordered Mr Trench.

He had to shout to make himself heard above the din of the coming tempest. And Stella, cool as ever in spite of the peril, sat absolutely still, steering as calmly as if they were rowing down the Thames.

Cyril saw with the tail of his eye the dark mass of rock loom up alongside. The boat's head swung inward.

At that moment the wind hit them. So great was its force that the boat spun like a chip on a mill-race, and the oar was almost wrested from Cyril's hand. All was darkness, confusion and a whistling hiss of rain and spray.

"Pull!" he heard Mr Trench roar out behind him, and somehow he got his blade again into the water, and tugged with all his might.

The next few moments were a blur to Cyril, and indeed to all of them. They could see nothing, while the roar of the gale was absolutely deafening and paralysing. Then came a great glare of lightning, and in its momentary gleam, Cyril caught a glimpse of the promontory, now behind the boat. Its jagged height broke the full force of the wind, and Stella still keeping her head, held the tiller hard over.

Foot by foot they forced the boat inward till at last, gasping and exhausted, they reached calmer water under the lee of the rock.

"Keep on!" shouted Mr Trench encouragingly. "Only a few strokes more. We're on the beach."

Cyril's arms were like lead, his back was one great ache, but he still pulled. A moment later, and the keel of the boat grated on sand, and she came to rest on a narrow strip of beach backed by a broken cliff some forty feet in height.

"And that's that," said Mr Trench with a sigh of relief. "Now get your breath, boys, then we must land, and get the boat up. If the wind shifts there'll be a sea here that would smash a ship."

Tim and Cyril were only too grateful for a moment's breathing space, but Mr Trench did not give them long. In less than two minutes he was out and on the beach. He, Cyril and Tim, between them, dragged the boat up, and got Stella out. Then Gregor had to be helped out, and after that they pulled the boat right up out of the water.

By this time the rain was coming down in sheets, and none of them could have been wetter if they had been swimming. The storm was at its height, and a thunder-storm in tropical Africa is a thing so much more terrible than anything of the kind in England as to be almost beyond description. There was no pause between the flashes, and thunder and wind together combined in an uproar that was nothing short of terrifying.

But Mr Trench remained steady as a rock. "There ought to be caves up there," he told them. "Indeed I know there are, for I explored this part during my first visit to the valley. Tim, you stay here with Stella and Gregor, and get what shelter you can under the cliff. Cyril, come with me and see if we can find a hole big enough to hide us all."

It was no joke clambering up the cliff face under such conditions, and Cyril had his work cut out for him to follow Mr Trench. But the latter seemed to know exactly what he was about, and finding a deep rift in which they were protected from the wind, went quickly upward.

"Ah, I thought so," he said presently. "Here we are, Cyril. Not much of a place, but still a port in the storm."

As he spoke he pushed his way in between two masses of rock, and Cyril saw that behind them a dark hole yawned in the face of the cliff.

Cyril was for pushing forward, but the big man checked him.

"Maybe some tenants already in possession," he said. "Not desirable ones."

As he spoke, he switched on an electric torch and let the light shine into the place.

It was just a hollow not more than twenty feet deep, about ten wide and low roofed. Rough as Nature had left it, but at any rate clean, bare and apparently empty.

"It will do," said Mr Trench in his curt way. "That is if—" He stopped, and did not finish his sentence, then turned abruptly back toward the beach.

Cyril wondered what was in his mind.

Inside ten minutes the whole party was in the cave. Mr Trench helped poor Gregor up, while the boys between them brought the food and the water, also the rifles.

The first thing that Mr Trench did was to serve out a dose of quinine all round, the next to knock open the case of food.

"We can't have any fire yet," he said, "but I think a meal will do us all good."

Now that the excitement of the last few hours was over they were all hungry, and they sat and enjoyed biscuits and tinned meat while the rain roared down and the thunder crashed. Outside a regular torrent was leaping down the little ravine on its way to the lake.

Mr Trench looked out on the war of elements. "Keep going," he said with a sudden smile. "Keep it up. You're our best friend for the present."

"And when 'tis over, sorr?" suggested Tim. "What thin?"

"Then, Tim, we've got to get out," replied their leader. "You may take it that Kent has a pretty good idea of where we are, and that he won't waste much time in coming after us. My notion is that, as soon as it's dark, we must embark again, and go straight down the lake, and join your people."

"Thin we'd best get all the slape we can first," said Tim. "I'm thinking 'twill be a mighty long pull."

"A most sensible remark, my young friend, and one to be acted on at once. So make yourselves as comfortable as you can, and sleep."

It was all very well to talk of sleep, but they were soaking wet, and the storm had brought the temperature down so many degrees that they were very chilly. Also, the cave floor was not an ideal bed. Though he was aching in every muscle Cyril could not get off to sleep, but lay there thinking and thinking of what was before them.

His thoughts were not very pleasant ones. It was a long way down to the foot of the lake, and there were only the three of them to row. As Mr Trench had said, Kent would not waste much time in getting or rather sending after them, and what earthly chance would they three, with two passengers, have against four rowers with none? Again, once they were started, they could not land, for undoubtedly Kent would have sent out his cannibals to patrol the whole shore of the lake. No, the prospect was not a rosy one, and the more he considered it the less Cyril liked it.

But rack his brain as he would, he could see no other way out, and at last, worn out, he dropped off to sleep.

A stirring close by roused him, and he sat up sharply. It was pitch dark in the cave.

"'Tis all right, Masther Cyril," came a whisper. "Sure, I've just woke up, and I'm thinking 'tis time we moved."

"Are the others asleep still?" asked Cyril.

"They are that. But come outside, and let's be seeing what the night's like."

The two slipped quietly out of the little cave. Night had fallen, but the storm was clean gone, and a million stars glowed in the quiet sky. Though there was no moon yet, it was not by any means dark.

"Any sign of Kent's people?" asked Cyril anxiously.

"Not that I can see," replied Tim, "but hush a minnit. I'm thinking there's something moving below there."

They were both silent, listening hard. From the woods behind came the usual night chorus of a tropical forest. Crickets chirped, frogs croaked and bleated, from the sky above came the soft droning of the night-jars swooping at insects. And from the lake was heard the occasional splash of some giant fish moving on the surface. For the moment that was all that Cyril could hear.

"It's all right," he whispered at last. "At any rate I can't hear oars."

"'Twas not oars I heard," replied Tim. "Twas something below there on the beach."

"On the beach? Goodness, Tim, you don't mean that Kent's men have landed there?"

"Faith, I hope not, but if they have we'd be seeing their boat easy enough. Come on a little further. But don't be making a noise."

There was no need for this warning. No snake could have moved more quietly than Cyril, as he stole forward to the edge of the little plateau in front of the cave.

Tim put his mouth close to Cyril's ear. "There's only wan boat," he said, "and that's ours."

Cyril did not answer at once. When he did his voice had a serious tone. "But you were right, Tim. There is something moving. I heard the gravel crunch."

"Sure, I thought I did, too," agreed Tim. "Is it thim niggers, do ye think?"

"I can't see any," replied Cyril, straining his eyes into the gloom under the foot of the bluff. "Ah, there it is again!"

"'Deed, I heard it meself," said Tim. "'Tis either a Karalek or some wild creature."

"Let's go a bit further," suggested Cyril. "I've got a pistol in my pocket."

Tim assented, and they began to work slowly down the slope. They were about half-way to the beach when there came a crunching so loud that both stopped short, and lay perfectly still. Cyril could feel his heart thumping as he lay.

"'Tis something mighty big," whispered Tim in Cyril's ear.

"Wait!" hissed back Cyril. "I see it, Tim; it's a snake."

"And the father of all the snakes," answered Tim. "Holy smoke, 'tis as big as the baste we jumped over back in the forest there."

A snake it was, or at any rate something of the sort. They could see it now as it came slowly across the strand from the direction of the lake. Its body looked as thick as a barrel, and its head was lifted some ten feet above the ground.

"Tim, it's got ears," muttered Cyril in a shaking whisper.

It had. Ears that looked as big as a donkey's, stuck out on either side of its terrible head.

"And it's coming up the cliff afther us," returned Tim, springing to his feet.

Cyril did not wait either, and the two went leaping back up to the cave-mouth.

"What's up?" It was Mr Trench's voice, sharp and almost angry.

"A snake, sir," Cyril answered. "A huge snake with ears. And it's trying to climb up the cliff after us."

Mr Trench snatched up a rifle. Then he dropped it hastily, and instead picked up an axe.

"We mustn't shoot. That would be fatal," he said, as he stepped out on to the ledge.

A moment all three stood there waiting. From below came a harsh rustling sound which steadily approached. Yet so far they could see nothing.

It was a horrible moment, so horrible that Cyril at least felt hardly able to breathe. Then quite suddenly some dark object showed between the two big rocks which stood on either side of the little platform, and a fearful head darted forward against them.

Quick as it was, Mr Trench was ready, the axe swung high and the monster was met by a terrific blow which landed clean upon the point of its snout-like jaws. So fierce was the blow that the keen edge of the axe bit deep and grated against the bone. With a bestial croak the nightmare monster dropped back, its weight as it fell wrenching the axe from Mr Trench's hands and nearly pulling him over after it.

Then with a thud and a rattle of loose stones the hideous thing fell away down the steep slope. It reached the beach and they heard it beating and thrashing about below in a most appalling manner, while a thick and sickening musky scent came beating up in waves.

"What was it?" Cyril managed to get out.

"An eel. One of those brutes out of the lake," replied Mr Trench.

"The same we saw through the glass window?" asked Cyril. "But—heavens! it was twice as big."

"They may grow a hundred feet long for all I know," answered the other. "I believe this lake is half a mile deep, and the things in it are not like anything else in the world. But even I didn't know that these brutes came out of the water."

"If one comes, there may be a dozen down there," shivered Cyril. "We can't risk taking Stella in the boat."

"If you could it would be no use," replied the big man, and for once he had lost all his usual cheerfulness. "Gregor's got fever, and badly, too. He woke up delirious, and it's out of the question to move him."

The news was so bad that Cyril could find no words. For a good half-minute the three remained speechless.

It was Tim who broke the silence. "Sure, there's only one thing to be done. Masther Cyril and me will go down the lake and fetch help."

"You boys?" exclaimed Mr Trench.

"Yes," said Cyril quickly. "Tim is right. We must chance the eels and get along at once. You see, Mr Trench, in any case the boat can't be left where it is. It's a dead give-away, for the minute Kent's men see it they'll know where we are."

"That is true," Mr Trench answered slowly. "Yes, I believe you are right. It may be a forlorn hope, but it's our only one."

He paused. "Get your rifles," he said. "As for me, I'll take you down to get the boat off. And Heaven send there are no more of these hideous brutes wandering on the beach."


CHAPTER XXIV
THE ARMOURED BOAT

STELLA had overheard the plan, and for a moment she clung to Cyril.

"Oh Cyril, I wish you hadn't to go!" she sobbed.

Cyril soothed her gently. "I must, dear. It's our only chance. And come to think of it, not a bad one. Tim and I will get a jolly long start before light, and you'll be safe enough here until we can come back for you. With the boat gone, Kent won't know where to look for you."

"But the eels, Cyril. Those dreadful things!" she whispered shivering. "Oh, I've seen them so often, and—and—"

"Don't worry, dear. Tim and I have our rifles. Besides I don't think they'd attack a boat. Cheer up and think of to-morrow when Father and your uncle will come in the 'Avenger.' There won't be much left of Kent and his lot by the time we have finished with them."

"Come, Cyril." It was Mr Trench's voice from outside, and Cyril, giving Stella a last hug, hurried out.

The beach was clear. The wounded eel had managed to writhe back into the water, and no more of its terrible company were in sight. Still it may well be supposed that the three did not waste much time about launching the boat, and as soon as ever it was afloat the two boys sprang in.

"Good-bye, lads. God bless you," said Mr Trench in his deep quiet voice, and they saw his tall figure dim in the starlight, as he stood on the narrow strip of beach, watching them away. Presently he turned, and went straight up the cliff again.

The lake was calm as glass, and beyond the occasional splash of some monster of the depths there was no disturbance of its placid surface.

"I'm wondhering where Kent's men are," said Tim presently, as he tugged at his oar. "Sure, 'tis funny he's not watching."

"It's on the cards that his boat was wrecked," answered Cyril. "She didn't get behind the point like we did."

"No such luck!" replied Tim rather despondently. "They were mighty near the shore whin I last saw thim."

"Cheer up. They aren't after us anyhow. And we've got the night before us."

Tim did not answer, but pulled steadily, and the boat, which was a well-built one, slipped easily across the calm water. They kept fairly near the shore, but far enough away to be out of reach of the spears of prowling Karaleks. And each had an eye lifting all the time for possible danger from the lake itself. Neither of them had forgotten the eel.

In an hour they were three miles down the lake, and rounding the outer end of a high point of rock, found land right opposite.

Both stopped pulling.

"Surely it can't be the end of the lake, Tim?" said Cyril, puzzled.

"'Tis not that," answered Tim decidedly. "It's miles we have to go before we rache that. I'm thinking 'tis an island."

"I expect that's it," allowed Cyril. "Well, let's pull on and see. But it seems to me that the channel between it and the land must be pretty narrow. I can't see it at all."

They pulled on, and presently found that Tim was right. The mass of land was an island, a great lump of volcanic rock sticking up out of the depths of the lake.

The channel dividing it from the shore was plainly visible, but very narrow.

"Hadn't we better go round?" suggested Cyril.

Tim shook his head.

"'Twould be another mile or more, and we'll nade all our strength before morning. 'Tis no great distance. Let's be slipping through quick and quiet."

Cyril made no further objection, and they began to pull through the channel. The channel itself was only about a hundred feet wide, and on either side rocks towered up black and grim. Even if the Karaleks had followed them this far it did not seem at all likely that they could harm them. They certainly could not get down to the water's edge.

The channel was about a quarter of a mile long and the boat had reached the midway point when there was a slight splash in front and the boat heaved to a sudden swell.

Both boys stopped pulling, and looked quickly round. Twenty yards ahead was a patch of broken water, but nothing else was visible.

"A fish!" said Cyril quickly.

"Faith, it must have been a whale to make that wave," Tim answered.

Cyril shivered slightly. "Pull on!" he said in a low voice.

"Wait!" said Tim sharply. "What's that undher the bank there?"

He pointed as he spoke.

There was no need for Cyril to answer, for at that very instant a boat shot out from the gloom under the bank, and came toward them at full speed.

"Trapped after all!" snapped Cyril, as he shipped his sculls and reached for his rifle.

While he thrust cartridges into his magazine, the boat came shooting out, and all of a sudden a fierce and hideous yell broke the gloomy silence and echoed back from the rocks on either side.

"Karaleks!" gasped Cyril.

"And in Kent's boat," added Tim quickly. "Faith, this is something new entirely. But what can they do against us? Sure, we can shoot thim to pieces before they come near us."

"Don't be so sure about that," snapped back Cyril. "What's that they've got in the bows? It's a shield of some sort."

"Will I give thim a shot?" asked Tim.

"Yes. Try one."

Next moment the crack of Tim's rifle woke thundering echoes. It was followed instantly by the sharp clang of a bullet striking steel.

"It's a shield," said Cyril swiftly. "This is Kent's work. He's fixed them up. Fire low, Tim, and hit the boat itself. It's our only chance."

The cannibals realizing that for once they were safe from the dreaded rifles, came on at a great pace. They were not rowing, but paddling. The boat, which was much the bigger of the two, was crowded with them, and while some paddled, the rest, safe behind the curved steel shield, began to fling their long, razor-headed spears.

Tim fired again three shots in quick succession. As Cyril had suggested, he fired low, but it seemed as though the whole boat was armoured, for after each shot came the same clang of lead on steel.

Cyril fired too, but with equally little success. Though not one bullet missed the boat, it did not stop, but came straight on. Spears began to rain in the water all around the boys. One actually struck their boat and, missing Tim by a few inches, stuck quivering in the stern-sheets.

"Lie down, Tim," cried Cyril. "If they get one of us we're done."

"I'm thinking we're done anyhow," growled Tim. "Who'd have dramed of Kent thrying a thrick like this?"

Cyril realized that Tim was right. The situation was practically hopeless. One lucky shot indeed did get a Karalek who had incautiously shown himself above the shield, and with a shriek he went overboard, but there were a dozen or more in the boat, and safe behind their armour; they could not be stopped. He fired and fired again, smashing several of the paddles, and for the moment stopping the way of the boat, but fresh paddles were thrust out, and the distance between the two craft narrowed every moment.

The cannibals were within thirty yards. They had stopped throwing their spears, and clearly meant to make a rush and capture the boys alive. Cyril shivered as he thought of the fate in store for them.

And then—then just at the last moment the water boiled again, and close under the side of the Karaleks' boat a huge head rose and a pair of gigantic jaws opened like a barn door, to close with a clang upon the wounded Karalek who was still struggling on the surface.

It was an alligator, but an alligator of such size as the boys had never dreamed of. The creature was nearly twice as long as the Karaleks' boat, and its head alone measured at least six feet in length.

Without pausing to think what he was doing Cyril fired straight at the monstrous head, and the bullet went home with a heavy thud.

The result was paralysing. The pain of the wound must have driven the monster mad, for dropping its prey, it shot up half its length out of the water to fall with a crash that sent great waves rolling. So close was it to the Karaleks' boat that the water rushed over the gunwale, half filling the craft.

The black men shrieked in frantic terror, and the boat swayed dangerously. The great brute's head vanished beneath the surface, then up came its huge scaly tail and fell like the flail of doom across the water-logged craft. With a splintering of planks, the whole boat melted away and sank beneath its shrieking crew.

The whole thing was so appallingly sudden that neither Cyril or Tim could find a word. They crouched in their boat in absolute silence while the boat itself rocked furiously on the waves.

"Look!" gasped Tim at last.

Several of the wretched Karaleks had started to swim toward the boys' boat, but the first was not ten strokes on his way before up went his arms, and he had hardly time to shriek before he was dragged down. In a moment the water all around was boiling, and the gloom of the gorge full of the hideous clashing of teeth as the savage denizens of the lake gathered to their feast.

Cyril seized his oars. "Pull, Tim. Pull! If we don't get away they'll have us too."

Next moment they were both rowing for dear life, and presently with feelings of intense relief they had left the dark strait behind, and were out again on the open lake.

Here they stopped pulling a minute to get breath.

"Praise be, we're out o' that, Masther Cyril!" said Tim gratefully.

"We're certainly lucky," Cyril answered. "That was a clever trick of Kent, to lay such a trap for us. Shows, too, he had a pretty good notion that we weren't drowned in the storm."

"And now we know his men weren't, either," put in Tim.

"That's true," agreed Cyril, "but come on, Tim. If we were in a hurry before, we must be in a bigger one now."

"What for? Sure we're miles from Kent's place, and I don't think 'tis more than another four or five to the ind of the lake."

"Four miles from Kent," repeated Cyril. "Yes, and on a night like this the sound of our shooting would carry pretty near fourteen. You can be dead sure Kent's heard it, or some of his men, and they'll be after us now just as quickly as ever they can shift."

"But sure, they've got no boat left."

"Boat! What do they want with a boat? They've got their airship."

Tim gasped. "Faith, I hadn't thought. Come on thin, Masther Cyril."

Again the oars dipped, and the boat drove on her way across the mysterious lake. What awful monsters were cruising beneath their keel the boys had no leisure to think. Their ears were straining for some sound of the airship's engines.

But time passed, and they heard nothing of the sort, and gradually they began to feel a little happier.

All the same Cyril was badly puzzled. He felt perfectly certain that the heavy firing must have reached Kent's ears, and he could not understand why he did not follow. The only possible explanation was that Kent was so certain that the Karaleks had been successful that he was only waiting for them to bring in the prisoners.

Another long hour dragged by; they passed another promontory running far out into the lake, and now the moon was rising and by its pale light they were able to see that beyond the lake narrowed rapidly. There was no doubt but that they were coming near the lower end, where the surplus water escaped into the river.

But even so they still had a long way to go, and both were getting deadly tired when at last they saw before them the mouth of the outlet. Another half-mile, and the pace quickened. Their boat was in the drag of the current. The banks closed in and they were floating in the centre of a broad stream which ran swiftly westward.

Almost worn out, their hands blistered, and their bodies wet with perspiration, the two instinctively stopped rowing, and let the boat drift.

"I'm thinking the worst is over," said Tim gratefully. "Wid this current to help us, we'll be down at the camp in a little while."

"We've certainly had wonderful luck so far," agreed Cyril, "but it beats me why Kent isn't after us. He simply must have heard all that shooting."

"Maybe his ship was damaged in the storm," suggested Tim. Cyril looked up quickly. "I hadn't thought of that, but it's quite likely. Something must have happened, for Kent would never have risked the chance of our getting away."

"'Tis Miss Stella I'm thinking of," said Tim presently. "I'll not be happy till we've got her and Misther Trench out of that hole in the rock."

"Nor I," replied Cyril, "but they'll be safe enough for the present. You see Kent will take it for granted that, if any of us have escaped, we've all gone together."

"'Deed thin I hope so, but 'tis a cunning fellow he is, and ye can't be sure what he knows, and what he doesn't. I belave—"

Cyril flung up a hand. "Hush!" he whispered. "What's that?"

The boat had swung round a fresh curve of the river, and a deep but distant droning had suddenly reached their ears.

Tim stiffened. "Begorra, 'tis the airship afther all!" he exclaimed.


CHAPTER XXV
IN PERIL OF WATER

FOR a few moments the two remained silent, listening intently. The sound grew plainer, but the odd thing was that it did not seem to come from the direction of the lake.

Tim realized this first.

"'Tis our own ship, I belave," he said sharply.

"That's what I was thinking. Oh, Tim, what shocking luck! She's going to look for us, but they'll never see us in this light, and we can never—never pull all that way back."

His words ended in a groan of despair. Cyril was more highly-strung than Tim, and the strain on both the boys during the past three days had been simply terrific.

Tim realized that his friend was very near the breaking-point.

"Be aisy," he said consolingly. "Sure, we're not certain 'tis the airship afther all. And why would Misther Hamer be starting in the night? The last thing he said was that he wouldn't be moving until he heard from us."

"But if it's not the 'Avenger' what can it be?" demanded Cyril.

Tim did not reply at once, but sat motionless, his quaint little head on one side, straining his ears. At last he spoke. "'Tis not an airship at all," he said with decision.

Cyril nodded. "I believe you're right after all, Tim. It's a deeper note altogether."

Tim broke in sharply. "I've got it. I know what's making the noise. 'Tis wather."

Cyril gave a low whistle. "Water? A fall, you mean."

"That or a rapid. I'm sure of it."

"Then we'd jolly well better get ashore or we'll be in it before we know it."

Tim glanced at the banks. They were regular cliffs rising straight up from the river, like walls.

"A mighty awkward place to be landing," he muttered, as they started to pull toward the left-hand shore.

"Pull harder!" said Cyril after a moment. "We're not getting on a bit."

"Faith, I'm nigh breaking me arms," returned Tim.

"And so am I," answered Cyril. "I say, Tim, the current's running a jolly sight faster than I thought."

"It is that. It's the moonlight's deceived us," panted Tim as he tugged at his sculls.

Slowly the boat drew nearer to the bank, but now both boys could see only too clearly that they were in the grip of a current against which they were far too exhausted to fight, and as the conviction forced itself on Cyril, he began to feel distinctly unhappy.

The roar of the rapid or fall was now getting closer every minute, and a very ominous sound it was. The river curved a quarter of a mile further down, so it was impossible to see what they were coming to, but certainly it was something pretty big and bad. If they could not find a landing place the chances seemed decidedly slim.

In a long slant they gradually approached the bank, but when they came near, it was only to find that it was all sheer rock. There was not a ghost of a landing place, and the water gurgled black and deep against the foot of an overhanging bluff.

By this time the roar had become a dull, heavy thunder. Coasting along the bank and watching eagerly, but quite in vain for any landing place, they presently swept round the curve, and from both at once came cries of dismay.

In front, and only a couple of hundred yards away, the river narrowed to a width of no more than fifty feet, and shot down a long, steep slope. The pale moonlight shone upon great tossing crests of snowy foam, and the roar and thunder of the rapid were deafening.

Cyril saw a cleft in the rocky bank, and driving one of his sculls into it, held the boat for a moment.

"Tim, we can never go down there. We'll be smashed to atoms," he cried in despair. Almost as he spoke the force of the stream drove the boat sideways, and the sudden drag splintered the blade of his oar.

"That's finished it!" he groaned.

"'Deed and it has," replied Tim, and in spite of the awful danger he spoke quite calmly. "We've got to go through wid it, whatever it is, so kape her out in the middle, and we'll do our best."

His coolness shamed Cyril. "Right!" he said between clenched teeth. "You steer, Tim. I'll stay in the bow and fend off if we meet rocks."

Tim took a few strokes and the boat shot out into the centre of the river. Then the full force of the current gripped her, and she flashed forward with the speed of a train.

Neither of the boys spoke again. In any case it was useless. The din and thunder of the warring waters drowned all other sounds. Almost before they knew it, the boat was in the rapids and tipping forward shot downward like a toboggan on an ice slide. Tim in the stern steered with one oar; Cyril in the bows kept watch in front.

After the first swift plunge, the boat struck a wave and reared like a frightened horse. She spun past a black rock, swerved, and a sheet of foam dashed over her. Tim managed to right her and she fled down a second slope. Ahead, Cyril saw a wild welter of roaring foam in which it did not seem possible that anything could live.

Suddenly he swung round. "To the left! Steer to the left, Tim!" he shouted at the pitch of his voice. He had seen in that direction a narrow channel between the jutting points of rock. Whether or not it was wide enough for the boat to pass he could not tell. All he did know was that it was their only chance.

Tim, understanding Cyril's gesture more than his words, flung his weight on the oar, and the boat swerved sharply to the left, and skimmed through the gap like a hare through a fence.

To his horror, Cyril saw another rock looming up ahead. Springing to his feet, he thrust at it frantically with his oar. Next moment he was flung back into the bottom of the boat and the back of his head struck a thwart with such force as stunned him. He lay quiet and still. But he had saved the boat from certain destruction. Just grazing the fatal rock, she shot straight down the central rapid, lifted to a last wave, then driving through a tumble of white water swam peacefully onward down a swift but smooth stream.

Tim rose, lifted Cyril, and dabbed his face with cool water from the stream. But Cyril did not stir, nor did his eyes open. Tim placed him in as comfortable a position as was possible, baled out the boat, then without a word took to his oars again, and pulled on steadily down the stream.

He was so utterly worn out that he was hardly conscious of what was happening or how the time passed. How long he kept on pulling he could not tell. But at last his swimming eyes caught a gleam of light across the placid stream.

"Who's that?" came a sharp challenge. The voice was Saunderson's.

"It's me. It's Tim M'Keown," Tim answered thickly, and turned the boat inshore. The next he knew, he was being lifted out by a pair of strong arms. After that he must have collapsed, for he did not remember anything more until a sting of strong spirit in his throat brought him abruptly back to consciousness.

"Stella—where is she? Have you found her?"

It was Mortimer Carne speaking, and his deep harsh voice thrilled with a feeling of which formerly Tim would never have believed him capable.

On the other side of the cot on which Tim found himself lying stood Mr Hamer, his thin, brown face drawn with anxiety.

"Miss Stella was safe whin we left her," Tim answered hoarsely. "How's Masther Cyril?"

"Coming round," answered his father, "but he can't talk yet. Can you tell us anything, Tim?"

"Sure I can," answered Tim more firmly. The old brandy with which he had been dosed was clearing his head. Some one brought a cup of hot coffee with milk, and he drank it greedily.

"Now I'll tell ye the whole story," he said, and this he did, while the others stood round, listening breathlessly.

"Thanks be," said 'Chilled Steel' Carne, as Tim finished. "So she is safe in the cave with this Mr Trench. We must fetch her at once—at once, Hamer. This is our chance. With Kent's ship disabled, we have it all our own way."

"I wouldn't be too sure about that," answered Tim. "'Tis only our suspicion that his ship's damaged. And if she is, ye may be sure he's doing his best to mend her. It's a fight ye'll be having before ye get the betther of him."

Carne's jaw set hard. "A fight! I'd ask nothing better than to have the chance of ridding the world of such vermin."

"Quite so, but our task is to rescue Stella," replied Mr Hamer in his quiet voice. "And we must not do anything rashly. What is your opinion, Tim? Do you think we should start at once?"

"I do, sorr," Tim answered firmly. "If 'tis thrue that Kent's ship is hurt, why the quicker we get afther him the betther. And if we can rache him before light, we've the chance to surprise the fellow."

Mr Hamer nodded. "Yes, I think you are right, Tim. It's quite clear that we must put Kent's airship out of commission before we attempt to rescue Stella and the others from the cave."

He turned to Saunderson, who stood by.

"How soon can you be ready?" he asked.

"Inside twenty minutes," was the brief reply.

"Then carry on," said Mr Hamer, and Saunderson was off like a shot.


CHAPTER XXVI
KENT SPRINGS A SURPRISE

WRAPPED in thick overcoats, Tim and Cyril stood together in the saloon of the "Avenger," and looked down upon the lake. The "Avenger" had risen silently to nearly ten thousand feet, and the great mysterious lake, with its wild surroundings of mountain and forest, lay like a map, almost two miles beneath them.

Cyril's head still ached from the blow, and both he and Tim were sore with fatigue. But good food, excitement, and the chill, thin, bracing air of the heights had put fresh life into them, and standing at the open window they were eagerly watching the scene below.

The "Avenger" was in full war trim. Her men were at their stations, bombs were ready in their clips, and the two machine-guns were uncovered and prepared for immediate use.

Tim had the glasses, and was scanning the south bank of the lake.

"Can you see Kent's ship?" asked Cyril breathlessly.

"I cannot," replied Tim in a puzzled tone. "The moonlight is a bit puzzling, but faith I'm almost sure she's not on her float."

"Not on her float! Tim, do you think the storm blew her away?"

"Sure, it almost seems like it," replied Tim.

"What gorgeous luck if it's true! If that's so, we've got nothing to do but just drop down and bomb the old temple-palace till they hoist the white flag."

He turned to Mr Hamer.

"Father, Kent's airship is gone from the float. We think it may have been blown away in the storm and smashed. Can you see anything of it?"

Mr Hamer, like Tim, was examining the country below with a powerful pair of binoculars.

"I can't see a trace of it, Cyril. I can see the old temple and the float. But there does not seem to be anyone moving about down below. I can't be sure of course from this height, and in this uncertain light."

"What shall we do?" asked Cyril. "Do you think it would be safe to drop a bit, and take a closer look?"

Mr Hamer hesitated. "We might drop a little, but I think we'd best hang pretty high until daylight. The sun will be up in less than an hour. See, the sky is turning pink already away toward the Sudan."

"I hate waiting," growled the ironmaster, breaking in suddenly. "The thought of Stella pinned in that miserable cave drives me mad. Cyril, are you sure that the niggers can't get at her?"

"I shouldn't think it's likely, sir," Cyril told him. "The cliff's pretty steep above the cave, and anyhow I don't think the Karaleks had any idea where we landed. You see it was in the worst of the storm, and it was so dark you couldn't see from the top of the cliff to the bottom."

Mr Carne did not answer, but his harsh face was wrung with such bitter anxiety that Cyril had never felt more sorry for him.

Orders were given, and the "Avenger" dropped a little. At this height there was a steady current of air from the south, and it was necessary to keep the muted engine going at half-speed in order to hold the great ship and keep her from drifting northward across the desert.

The eastern sky grew rapidly brighter, though below the valley was still wrapped in night only faintly illuminated by the half-moon.

"Another half-hour," said Mr Hamer, and even as he spoke there was a faint, thin, whistling sound which made every one start and look round.

It grew to a shriek, and something whizzed past the "Avenger" like a meteor, missing her by a matter of only a few yards.

From the look-out platform the telephone buzzed. Mr Hamer sprang to the instrument.

A moment of breathless suspense, then Mr Hamer spun round.

"It was a bomb!" he snapped. "Kent's airship is not destroyed. She is above us this minute,"

Snatching up another telephone, he gave sharp orders.

"Up with her, up to the limit. And full engine-power!"

With a deafening roar all the great motors burst at once into full life, and the "Avenger" shot forward like a frightened fish.

Only just in time, for at that moment a second bomb came screaming past through the very space they had just left.

"It's his hydrogen," explained Mr Hamer. "Gives him a slightly greater lift than our helium gas. But the cunning of him! He must have either seen or heard us coming and climbed at once."

From the depths below came up a deep boom as the second bomb exploded with appalling force, but this hardly anyone noticed, for just then there broke out the thin, sharp sputter of a machine-gun, and bullets sprayed the "Avenger," cutting through the fabric of her envelopes and clanging viciously on the metal of her car. But the range was considerable, and by this time the big ship had got into her stride. She was moving northward and upward in a long, swift slant. For the moment she was simply running away for all she was worth.

It was the only thing to do. Since Kent had cunningly managed to get the weather-gage, it was her one chance for safety; and even as it was the peril was frightful, for Kent, dropping from above, could travel at least as fast as the "Avenger," and all aboard the "Avenger" herself knew that if one of his bombs did strike them it was the end.

The boys stood breathless. For the moment there was nothing they could do. All depended on whether the "Avenger" could get clear before she was damaged beyond repair.

The sputter of Kent's machine-guns sounded nearer, and from the look-out came the news that his craft was driving straight down at them with all her power.

With the ear-pieces fixed on his head, Mr Hamer was steering. Suddenly he flung the wheel over, and the great ship spun so suddenly that the boys reeled across the cabin.

Her nose dropped, and instead of climbing she swooped downward.

For the moment Cyril was utterly dismayed, but only for a moment.

Then he understood.

"It's to give our engines their chance," he said to Tim. "We're faster than Kent. Father means to get out of range first. Then he can rise and try for the weather-gage."

Tim nodded. But in spite of the increased speed the rattle of the machine-gun grew louder. The range was closing. A bullet, penetrating the metal roof of the car, struck the glass of the windows and shivered it with a crash.

"This is getting pretty hot," said Cyril. "Can't we shoot back?"

"He's too close above us, I'm thinking," Tim answered. Then with a start—

"Begorra, what's that?"

A great glare of greenish light had eclipsed the dawn, and a fierce hissing sound made itself heard.

"Flaming onions!" gasped Cyril. "The things the Germans used against our 'planes."

Almost before he had finished speaking, the "Avenger" seemed to be wrapped in the fierce green glow.

"Buckets, all hands with buckets!" roared Saunderson, and the boys leaped to help.

Outside, on the cat-walk, they met such a gale they could hardly stand, for the "Avenger" was flashing through the dawn at something not far from a hundred miles an hour.

The cold of the blast was frightful.

But no one thought of that. All they did think of was great patches of glowing sparks clinging to the fabric and woodwork of the machine, where Kent's diabolical firework had struck her.

For five minutes, which, to Cyril at least, seemed like five hours, they struggled fiercely to save the airship from destruction; and while they fought the flames, Kent's guns rattled constantly and bullets rained around them. Saunderson was hit in the calf of the leg, but fortunately it was a mere graze, and Tim's coat-sleeve was cut by another bullet, which raised a blister on his arm without drawing blood. The gas-bags were pierced again and again, but the stuff of which they were made closed up again and not enough gas was lost to affect the buoyancy of the ship.

Bucket after bucket was passed, the flames were quenched, the smouldering patches were blackened out, one by one, and at last a triumphant shout from Saunderson announced that the last was out, and the danger over.

Panting, Cyril clung to a stay and looked back. Kent's airship was now in full sight, still slightly higher than the "Avenger." She was now a good half-mile behind, and losing every moment. Her guns still crackled, but they were no longer dangerous.

"We've done 'em," said Saunderson, coming up close to Cyril. "We've got the legs of 'em. Barring accidents, they'll never touch us again."

Tim came struggling back along the cat-walk. "I'm froze," he said. "Let's be getting under cover."

They scrambled back to the car, and dropped down through the hatch in the roof. Mr Hamer was still at the wheel. His great engines roared triumphantly.

"Is the fire out?" was his first question.

"'Tis out, sorr," Tim answered, "and no harm's done to anybody to speak of. What's more, we've bate Kent hollow, and I'm thinking our turn's coming."

A quiet smile crossed Mr Hamer's face.

"I knew the 'Avenger' was far faster than my first craft. It's not only my new engines, but the Stellol fuel. And, my boys, be thankful we are using helium, not hydrogen. If Kent's ship had been attacked like ours, there would now be nothing left of it but cinders."

"But what are we going to do now?" asked Cyril eagerly. "We're not going to keep on running away."

"We are for the present," replied his father firmly. "I mean to have plenty of room before I rise again to attack him."

Cyril turned back to the window. Kent's ship was now a good mile away. She was still driving at full power in pursuit. But she was also beginning to rise again.

Cyril told his father.

"Don't trouble yourself, my boy," replied Mr Hamer with calm confidence. "Now that we have escaped the first surprise I have Kent in the hollow of my hand."

He glanced at the gauge in front of him.

"Just under ten thousand feet," he said musingly. "And speed eighty-seven miles. What do you reckon the other is doing, Cyril?"

"Not much more than seventy, judging by the way we are losing her."

Mr Hamer nodded. Again he spoke through the telephone, then began himself to work the rudders and steering-vanes.

The "Avenger's" nose tilted upward again.

"Watch Kent!" said Mr Hamer. "Keep me posted as to his position."

There was a pause, during which the only sound was the deep roar of the "Avenger's" engines.

"We're two miles ahead, Father, and quite as high," said Cyril presently.

"Tell me when we are higher," replied the other.

Again a pause. The "Avenger," utilizing all the extra power of her engines and at the same time emptying her ballast tanks, was driving upward at a great pace. The air grew colder every moment, and frost-fingers began to form on the glass of the closed window of the car.

"We're higher than he," called out Cyril. "We're gaining fast."

"Ah, I thought so. Kent must have emptied his tanks to get above us in the first place. Now he has no reserves of buoyancy."

Tim heard and chuckled.

"Sure, we've got him cowld," he said.


CHAPTER XXVII
A BATTLE IN MID-AIR

BY this time the sun was climbing over the eastern rim of the world, and thin fleecy streaks of cirrus-cloud which lay a little way overhead had turned to crimson and gold. The yellow light fell, too, on Kent's ship, throwing up her long and beautiful lines.

Cyril suddenly remembered that day when he had first seen her model in his father's workshop, and sighed. It seemed cruel that a thing of such beauty should have to be destroyed.

But he hardened his heart. After all, it was Kent, not his father, who had built her, and no fate could be too bad for Kent and his crew of rascally pirates.

And as he watched, the "Avenger" rose and rose until the barograph indicated fourteen thousand feet, and Kent, still straining in pursuit, was three miles behind, and more than a thousand feet below.

"We've got the gage of them now."

It was Mr Carne who spoke, and his voice grated like a rusty saw.

Mr Hamer merely nodded, but his hands were busy, and the "Avenger" began to swing.

The two boys could hardly breathe for sheer excitement. The positions now were rapidly being reversed; the "Avenger" was rising right above the enemy, and Kent, strive as he would, could not hope to regain his former advantage.

"What will he do?" breathed Tim.

"Run for it," Cyril answered briefly.

"But what good will that be doing him?"

"Not a bit. It's only a matter of staving off the end for a few minutes.

"See, he's turning!" he cried sharply.

It was true. Kent, realizing that he had lost his chance, was wheeling and making away toward the north-east. The "Avenger" followed hard after.

Inside a minute her advantage was plain.

"We're gaining," cried Tim. "Sure, we're going nigh twice as fast as he."

Cyril could not speak. Excitement held him speechless, almost breathless. For now the "Avenger" seemed to sense that she was the hunter and not the hunted, and the pace at which she swept through the sky was almost incredible. With every beat of her powerful engines she overhauled the enemy.

Within five minutes she was within range, and now her guns began to speak. Kent's, too, woke to life, and the quiet dawn was torn with the hammer-and-rattle of firing and the swish of lead.

Kent had now given up all hope of rising to the "Avenger's" level. He was dropping fast, doing all his ship could do to escape from the deadly hail that scourged him from above.

But fast as he flew, the "Avenger" flew faster, and before they reached the opposite side of the lake the "Avenger" was almost on his tail.

Mr Carne, mad with excitement, had flung out of the cabin and was frantically urging Saunderson and the others to smash the scoundrel.

The "Avenger's" machine-guns were now firing Pomeroy bullets. Cyril and Tim could plainly see them striking Kent's craft.

"She's afire!" shrieked Tim suddenly. "She's burning."

Mr Hamer looked round. "Tell them to stop firing," he cried sharply.

Tim dashed out to do his orders, and almost instantly the firing ceased.

Cyril, watching through the open window, saw a pale streak of flame creeping along the side of Kent's airship.

"She's done for," he said.

Mr Hamer's face was twisted with pain. "It's ghastly," he groaned. "Blackguards as they are, such a fate is too awful. Cannot we help them in any way?"

Cyril shook his head. "There is no quarter in this kind of fighting, Dad," he answered. "And how much do you think that Kent would have given us if our positions were reversed?"

He broke off sharply. "She's gone!" he gasped.

As he spoke a huge jet of flame and smoke leaped from Kent's ship, and with a violent explosion the vast body of her doubled and broke in two, and she began to sink downward toward the lake.

At the same moment little figures looking no larger than flies dropped away from below her.

"Parachutes!" cried Cyril. "Her crew are going overboard with parachutes."

Mr Hamer snapped orders through the telephone. The engines stopped and the "Avenger" began to drop quickly.

"Where will they land?" questioned Mr Hamer.

"Somewhere upon the mountain-side, I fancy," Cyril answered. "We're a good bit beyond the lake."

His father gave a sigh of relief. "Thanks be, it's not in the lake. We could never have saved them."

At that moment Mr Carne came dropping through the hatch. "What are you doing, Hamer? Where are you going?" he demanded angrily.

"To pick up Kent and his men," answered the other.

"What! Waste time on those ruffians! Hamer, you are crazy. Stella must be our first thought."

"But the wretched men will perish in that wilderness," objected Mr Hamer.

"Let 'em," snapped Mr Carne. "Nothing that could happen to them would be too great a punishment. Have you forgotten Kent's threat—that he would leave Stella to the mercy of these foul cannibals?"

Mr Hamer looked doubtful, and a little confused Cyril cut in.

"We can think of them afterward, Father. I'm sure we ought to find Stella first. You must remember that the Karaleks may be after them."

Mr Hamer's face cleared. "You are right, Cyril. We will leave the fellows for the present. Our first duty is to Stella."

He gave fresh orders, and the "Avenger," now at a low level, swung back across the lake toward the bluff which Cyril pointed out. At the top of the bluff was a fairly open space covered with thin scrub, and here the airship settled quietly down.

Mr Carne could hardly wait till she was at rest. He was mad with impatience. The moment the ladder was lowered he flung himself down it, and in company with the two boys ran hard for the edge of the bluff.

But Cyril reached it first.

"Mr Trench!" he shouted at the top of his voice.

Next moment the tall, weather-beaten figure of the explorer stepped out upon the platform beneath. Behind him came Stella herself, her thin face bright with delight. "Uncle!" she cried, holding out her arms.

"Good for you, boys!" said Mr Trench, with hearty approval. "I knew you'd do the job somehow, though I confess I was scared stiff when I heard all that shooting last night. But you'll have to bring a rope to get us up."

Tim flew back to fetch one, and Stella was the first to be brought up. Her uncle snatched her up in his arms, and for the first time in living memory there were tears in the grim eyes of 'Chilled Steel' Carne.

It was harder work to get up poor Gregor. The fever had left him, but he was weak as a child. A boatswain's chair had to be rigged, in which he was lifted. He was at once put to bed in the after-cabin of the "Avenger," and Mr Trench, who knew a good deal about medicine, dosed him from the "Avenger's" drug-chest.

Meantime a sharp look-out was kept for the Karaleks, but there was no sign of them.

Mr Hamer, Mr Carne, Mr Trench, with Stella and Cyril, gathered in the main cabin, and here breakfast was served.

After all the excitement they were more than ready for the meal.

"But where's Tim?" asked Stella as they sat down round the long, narrow table.

As she spoke Tim came in. He was carrying his glasses.

"They've gone," he announced in great excitement.

"Who have gone?" demanded Cyril.

"Kent and thim others. Six of thim. Sure, I've just seen thim making over the top of the mountain out for the desert beyant!"

Mr Carne looked at Mr Hamer. "That saves us some trouble," he said, with a dry smile.

"Are you sure?" inquired Mr Hamer.

"'Deed, I am, sorr. They're a mighty fine pair of glasses, and showed thim fellows plain as plain cud be, right on the rim of the rocks."

"Then where are they going?" inquired Mr Hamer, wonderingly.

"Anywhere so they can get away from thim niggers, sorr," replied Tim with a grin.

Mr Trench spoke up. "They are wise," he said grimly. "Every one of those Karaleks knows just what has happened. They are all aware that Kent has been defeated, and he would get very short shrift if they once got their black paws on him."

"Sure, that's what I thought meself, sorr," said Tim. "They'll be making for the caravan road to the east."

"That's it without a doubt, though unless they have their rifles they won't get far."

"We need not trouble about them," said Mr Carne impatiently. "The one thing I am anxious to do is to get away from this abominable place. I propose that we start at once on our return journey."

Mr Trench looked at the ironmaster. "Are you going to leave me here at the mercy of those cannibal gentlemen?" he inquired softly.

"No—no, of course not. You will come with us."

"Thank you, but it's a long and expensive journey to get here, and this is where my business lies for the present."

"What business?" snapped Mr Carne.

"Exploring the place. Cataloguing the amazing plants and animals. Examining the extraordinary ruins."

"But, man alive," replied 'Chilled Steel' Carne impatiently, "surely you've had enough of it! And you can't possibly stay here alone in the midst of these cannibals."

"Exactly. To say truth I was relying on you to clear them out before you leave."

"To clear them out? Impossible! It would take weeks." Mr Carne looked both angry and upset.

Mr Trench remained calm. "Not more than twenty-four hours, I think," he replied mildly.

"Why, what do you mean?" demanded the ironmaster.

Mr Trench turned to Mr Hamer. "If you will give orders to rise, I think I can soon show you," he said courteously.


CHAPTER XXVIII
THE END OF THE KARALEKS

OWING to the "Avenger's" peculiar construction, she could rise or descend with equal ease, and it was but a matter of half an hour before she was in the air again, and over the lake.

Mr Trench stood on the platform above the main cabin, with Tim's field-glasses at his eyes. He was looking in the direction of the temple.

"Just as I thought," he said. "There they are."

He pointed as he spoke, and even without the aid of glasses, Cyril could see the Karaleks swarming about the great building.

"Looting," said Mr Trench briefly. "Now's our chance to wipe them out."

Mr Carne, who stood close by, stared. "What, you mean to kill the lot?" he said in a horrified voice.

"Much the best thing to do," replied the other. "They are nastier in their habits than any wild beasts, and far more dangerous. Leave them here, and they will increase and multiply and inevitably murder and devour anyone else who happens to visit this wonderful valley. It would be impossible to catch them and convey them back where they came from, and if we could do so we should only be letting loose a plague on their neighbours."

He turned to Cyril. "You and Tim have seen them at close quarters. What do you say?"

Cyril's face hardened. "I say it's the only thing to do, sir."

Mr Carne shrugged his shoulders. "Very well. What will you do?"

"A bomb or two first, then the machine-guns," replied Mr Trench sternly. "Tell your father, please, Cyril."

Mr Hamer didn't like it, and said so. Indeed he flatly refused to agree to the wholesale extermination of the cannibals. "One bomb, if you like," he said. "Then we will drop and force the rest to surrender."

Cyril shrugged his shoulders, but did not answer. Even if the Karaleks did surrender, he could not for the life of him imagine what they were going to do with a couple of hundred treacherous, bloodthirsty prisoners.

Presently the "Avenger" was right over the temple. And as she hung there, suddenly out of the big doors rushed a party of the Karaleks, carrying between them the dead and mangled body of the unfortunate Chin Su, the Chinese cook.

"The brutes!" he cried, his blood boiling. Tim had seen it too, and so had all the rest, including Saunderson.

"I'll settle 'em, the murdering dogs!" growled the Scotsman, and Cyril saw him hurry to one of the bomb levers.

There was a moment's pause while the "Avenger" was moved until directly over the cannibals. They, seeing the airship above them, had dropped their prey, and were bunched together, pointing upward, grimacing, and shouting what were probably insults.

Steadily the great airship swung over them. She had risen a little, so as to take no harm from the uplift of the exploding bomb.

Suddenly Saunderson pulled over the lever, and the long grey steel tube, carrying its deadly load, dropped and went whistling downward.

Saunderson's calculatings were well-nigh perfect. The bomb struck the earth within ten yards of the group of shrieking fiends. With a detonating roar it burst, and up leaped a vast fountain of red earth and rock and smoke, hiding everything over a wide area.

High as she was, the "Avenger" quivered in the shaken air.

"That's done it!" cried Tim in fierce delight. "That's finished the spalpeens!"

No one answered. No one spoke, for every soul aboard the "Avenger" who could see the ground, was standing stock still, breathless, hardly able to believe their eyes.

There came a cry from Tim.

"'Tis an earthquake," he gasped.

Still none of the rest answered, for they were staring, fascinated, at the amazing spectacle beneath. The whole ground was moving; all that slightly sloping piece on which the old temple stood, was sliding slowly forward toward the lake Slowly at first, then more and more rapidly the torn ground moved, and from beneath came up a terrifying thunder of sound.

The lakeward end of the temple dipped toward the lake, and the water rose in waves as the immense mass of the building shot outward like a vast ship being launched from the stocks.

As the pace of the slide increased, the waves rose into huge swells tipped with foam which shone like snow in the brilliant morning sunlight.

The main body of the Karaleks was inside the building, looting. Some came staggering out by the landward gate, but they did not get far, for at the point where the "Avenger's" bomb had fallen, a huge crevasse had opened, a great ragged rift which widened every second. The temple itself began to crack in every direction. The massive stones of which it was built dipped inward, one upon another.

Then, with a deafening roar, everything seemed to give way at once, and in a cataract the whole thing, the building and the site on which it stood, rushed forward, and was swallowed up in the great depths of the crater-lake.

Stunned by the suddenness and completeness of the catastrophe, the crew of the "Avenger" stood looking down on the boiling yellow whirlpools in which Kent's stronghold had disappeared.

"There goes the most wonderful relic in all Africa," said Mr Trench with great bitterness.

"And a couple of hundred of the worst niggers in the world. Don't be forgetting thim, Misther Trench," added Tim.

"You'll have a free hand with your investigations now, sir," said Cyril.

Mr Trench nodded. "That is true," he said.

Then he turned to Mr Hamer. "I want to have a talk with you and Mr Carne," he added. "A matter of business. Can we go into the cabin?"

They went, and the two boys and Stella were left alone. Stella slipped her arm through Cyril's, and he heard her sigh with relief.

"You're glad it's gone, Stella, I'll be bound," he said quietly.

"I can't tell you how glad," answered Stella.

The conference did not last very long, and presently Mr Hamer came up again. His usually grave face wore a smile, his eyes were bright.

"Cyril," he said, "we're not going to leave just yet."

"Hurrah!" cried Cyril. "I was just hating the idea of clearing out before we'd seen any more of this wonderful place. But what's going to happen?"

"When we do leave we are going to carry a cargo, Cyril. A cargo that, I hope, will pay all our expenses, and a trifle over."

Cyril's eyes widened. "What is it, Father—gold?"

"Better, my boy. Mr Trench tells us he has found a deposit of iridium."

"Iridium—that's the stuff they tip fountain pens with," said Cyril.

"It is. It is one of the most valuable of all metals, and at present is worth seven times as much as gold. The 'Avenger' will, I believe, carry home the richest cargo an airship ever has carried."

From Tim came a satisfied chuckle. "Thin, sorr," he said in his richest brogue, "ye'll have to be finding a new name for her. Sure, there's nothing left to avenge any longer."


THE END


Roy Glashan's Library
Non sibi sed omnibus
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