HAMILTON HAMMOND started nervously as the voice of Cullen, the expedition's chemist, sounded from his station aft. "I see something!" he called.
Ham bent over the floor port, staring into the eternal green-gray fog that blankets Uranus. He glanced hastily at the dial of the electric plumb; fifty- five feet, it said with an air of positiveness, but that was a lie, for it had registered that same figure for a hundred and sixty miles of creeping descent. The fog itself reflected the beam.
The barometer showed 86.2 cm. That too was an unreliable guide, but better than the plumb, for the intrepid Young, four decades earlier in 2060, had noted an atmospheric pressure of 86 in his romantic dash from Titan to the cloudy planet's southern pole. But the Gaea was dropping now at the opposite pole, forty-five thousand miles from Young's landing, and no one knew what vast hollows or peaks might render his figures utterly useless.
"I see nothing," Ham muttered.
"Nor I," said Patricia Hammond, his wife—or more officially, biologist of the Smithsonian's Gaea expedition. "Or—yes! Something moved!" She peered closer. "Up! Up!" she screamed. "Put up!"
Harbord was a good astrogator. He asked no questions, nor even took his glance from his controls. He simply slapped the throttle; the underjets roared in crescendo, and the upward thrust pressed all of them hard against the floor.
Barely in time. A vast gray wave of water rushed smoothly below the port, so close that its crest was carved by the blast, and spray clouded the glass.
"Whew!" whistled Ham. "That was close. Too close. If we'd touched that it would have cracked our jets for sure. They're white-hot."
"Ocean!" said Patricia disgustedly. "Young reported land."
"Yeah, forty-five thousand miles away. For all we know this sea is broader than the whole surface of the Earth."
She considered this, frowning. "Do you suppose," she asked, "that this fog goes right down to the surface everywhere?"
"Young says so."
"But on Venus the clouds form only at the junction of the upper winds and the underwind."
"Yes, but Venus is closer to the Sun. The heat here is evenly distributed, because the Sun accounts for practically none of it. Most of the surface heat seeps through from within, as it does on Saturn and Jupiter, only since Uranus is smaller, it's also cooler. It's cool enough to have a solid crust instead of being molten like the larger planets, but it's considerably colder than the Venusian twilight zone."
"But," she objected, "Titan is as cold as a dozen Nova Zemblas, yet it's one perpetual hurricane."
He grinned. "Trying to trip me? It isn't absolute temperature that causes wind—it's differences in temperature between one place and another. Titan has one side warmed by Saturn, but here the warmth is even or practically even, all around the planet, since it comes from within."
He glanced suddenly at Harbord. "What are we waiting for?" he asked.
"For you," grunted the astrogator. "You're in command now. I command until we sight the surface, and we've just done that."
"By golly, that's right!" exclaimed Ham in a satisfied voice. On his last expedition, that to the night side of Venus, he had been technically under Patricia's orders, and the reversal pleased him. "And now," he said severely, "if the biologist will kindly step aside—"
Patricia sniffed. "So you can pilot us, I suppose. I'll bet you haven't a single idea."
"But I have." He turned to Harbord. "Southeast," he ordered, and the afterjets added their voices to the roar of the others. "Put up to thirty thousand meters," he continued, "we might run into mountains."
The Gaea, named for the ancient goddess of Earth, who was wife to the god Uranus, plunged through the infinity of mist away from the planet's pole. In one respect that pole is unique among the Sun's family, for Uranus revolves, not like Jupiter or Saturn or Mars or the Earth, in the manner of a spinning top, but more with the motion of a rolling ball. Its poles are in the plane of its orbit, so that at one point its southern pole faces the Sun, while forty-two years later, halfway around the vast orbit, the opposite pole is Sunward.
Four decades earlier Young had touched at the southern pole; it would be another forty years before that pole again saw noon.
"The trouble with women," grumbled Harbord, "is that they ask too many questions."
Patricia spun on him. "Schopenhauer!" she hissed. "You ought to be grateful that Patrick Burlingame's daughter is lending her aid to a Yankee expedition!"
"Yeah? Why Schopenhauer?"
"He was a woman-hater, wasn't he? Like you!"
"Then he was a greater philosopher than I thought," grunted Harbord.
"Anyway," she retorted acidly, "a couple of million dollars is a lot of money to pay for a square mile of foggy desert. You won't hog this planet the way you tried to hog Venus."
She was referring, of course, to the Council of Berne's decision of 2059, that the simple fact of an explorer's landing on a planet did not give his nation possession of the entire planet, but only of the portion actually explored. On fog-wrapped Uranus that portion would be small indeed.
"Never mind," put in Ham. "No other nation will argue if America claims the whole fog-ball, because no other nation has a base near enough to get here."
That was true. By virtue of its possession of Saturn's only habitable moon, Titan, the United States was the only nation that could send an exploratory rocket to Uranus. A direct flight from the Earth is out of the question, since the nearest approach to the two planets is 1,700,000,000 miles. The flight is made in two jumps; first to Titan, then to Uranus.
But this condition limits the frequency of the visits enormously, for though Saturn and Earth are in conjunction at intervals of a little over a year, Uranus and Saturn are in conjunction only once in about forty years. Only at these times is it possible to reach the vast, mysterious, fog-shrouded planet.
So inconceivably remote is Uranus that the distance to its neighbor, Saturn, is actually greater than the total distance from Saturn to Jupiter, from Jupiter to the asteroids, from these to Mars, and from Mars to the Earth. It is a wild, alien, mystery-cloaked planet with only icy Neptune and Pluto between it and the interstellar void.
Patricia whirled on Ham. "You!" she snapped. "Southeast, eh! Why southeast? Just a guess, isn't it? Truthfully, isn't it?"
"Nope," he grinned. "I have my reasons. I'm trying to save whatever time I can, because our stay here is limited if we don't want to be marooned for forty years until the next conjunction."
"But why southeast?"
"I'll tell you. Did you ever look at a globe of the Earth, Pat? Then maybe you've noticed that all continents, all large islands, and all important peninsulas are narrowed to points toward the south. In other words, the northern hemisphere is more favorable for land formation, and as a matter of fact, by far the greater part of the Earth's land is north of the equator.
"The Arctic Ocean is nearly surrounded by a ring of land, but the Antarctic's wide open. And that same thing is true of Mars, assuming that the dark, swampy plains are old ocean beds, and also true of the frozen oceans on the night side of Venus.
"So I assume that if all planets had a common origin, and all of them solidified under the same conditions, Uranus must have the same sort of land distribution. What Young found was the land that corresponds to our Antarctica; what I'm looking for is the land that ought to surround this north polar sea."
"Ought to, but maybe doesn't," retorted Pat. "Anyway why southeast instead of due south?"
"Because that direction describes a spiral and lessens the chance of our striking some strait or channel between lands. With a visibility of about fifty feet, it wouldn't take a very wide channel to make us think we were over ocean.
"Even your English Thames would look like the Pacific in this sort of fog, if we happened to come down more than half a hundred feet from either bank."
"And I suppose your American Mississippi would look like Noah's flood," said the girl, and fell to gazing at the gray waste of fog that swirled endlessly past the ports.
Somewhat less than an hour later the Gaea was again descending gingerly and hesitatingly. At 85 cm. of air pressure Ham had the rocket slowed almost to a complete stop, and thereafter it dropped on the cushioning blast of the underjets at a speed of inches per minute.
When the barometer read 85.8 cm., Cullen's voice sounded from the stern, where the port was less obscured by the jets them-selves. "Something below!" he called.
There was something. The fog seemed definitely darker, and features or markings of some sort were visible. As the ship settled slowly, Ham watched intently, and at last snapped out the order to land. The Gaea dropped, with a faint jar, to a resting place on a bare, gray graveled plain domed with a hemisphere of mist that shut off vision as definitely as a wall.
There was something wild and alien about the limited scene before them. As the blast died, all of them stared silently into the leaden-hued vapors and Cullen came wordlessly in to join them. In the sudden silence that followed the cutting of the blast, the utter strangeness of the world outside was thrust upon them.
Venus, where Pat had been born, was a queer enough world with its narrow habitable twilight zone, its life-teeming Hotlands, and its mysterious dark side, but it was twin sister to the Earth.
Mars, the desert planet with its great decadent civilization, was yet stranger, but not utterly alien. Out on the moons of Jupiter were outlandish creatures of bizarre little worlds, and on cold Titan, that circled Saturn, were fantastic beings born to that wild and frigid satellite.
But Uranus was a major planet, no more than half-brother to the little inner worlds, and less than cousin to the tiny satellites. It was mysterious, unrelated, alien; no one had ever set foot on a major planet save the daring Young and his men forty years before.
He had explored, out of all the millions of square miles of surface, just one square kilometer forty-five thousand miles away from where they stood. All the rest was mystery, and the thought was enough to subdue even the irrepressible Patricia.
But not for long. "Well," she observed finally, "it looks just like London to me. Same sort of weather we had last time we were there. I think I'll step outside and look for Piccadilly."
"You won't go out yet," snapped Ham. "I want an atmospheric test first."
"For what? Young and his men breathed this air. I suppose you're going to say that that was forty-five thousand miles away, but even a biologist knows that the law of diffusion of gases would keep a planet from having one sort of air at one pole and another at the opposite. If the air was safe there, it is here."
"Yeah?" asked Ham. "Diffusion's all right, but did it ever occur to you that this fog-ball gets most of its heat from inside? That means high volcanic activity, and it might mean an eruption of poisonous gases somewhere near here. I'm having Cullen make a test."
Patricia subsided, watching the silent and efficient Cullen as he drew a sample of Uranian air into an ampule. After a moment she flexed her knees and asked, "Why is the gravitation so weak here? Uranus is fifty-four times as large as the Earth and fifteen times as massive, yet I don't feel any heavier here than at home." Home to Pat, of course, was the little frontier town of Venoble, in the Venusian Cool Country.
"That's the answer," said Ham. "Fifty-four times the size of the Earth or Venus, but only fifteen times as heavy. That means its density is much smaller—to be exact .27. Figures out to about nine-tenths the surface gravitation of the Earth, but it feels to me almost equal. We'll check a kilogram weight on the spring balance after a while and get an accurate figure on its mass.
"Safe to breathe?"
"Perfectly. Argon's an inert gas, and a substance can't possibly be poisonous unless it can react chemically in the body."
Pat sniffed. "See? It was safe all the time. I'm going outside."
"You'll wait for me," he growled. "Every time I've indulged that reckless disposition of yours you've got into trouble." He checked the thermometer beyond the port, nine degrees centigrade—the temperature of late autumn back home. "There's the cause of this perpetual fog," he observed. "The surface is always warmer than the air."
Pat was already pulling a jacket over her shoulders. Ham followed suit, and fell to twisting the handle of the air lock. There was a subdued hissing as the slightly denser Uranian air forced its way in, and he turned to speak to Harbord, who was lighting a pipe with great satisfaction—an indulgence strictly forbidden in space, but harmless now that an air supply was assured.
"Keep an eye on us, will you?" Ham said. "Watch us through the port, just in case something happens and we need help."
"We?" grunted Harbord. "Your wife's out of sight already."
With a muttered imprecation, Ham spun around. It was true. The outer door of the air lock was open, and a lazy wisp of fog drifted in, scarcely moving in the utterly stagnant Uranian air.
"The crazy little— Here! Give me that!" He seized a belt with twin holsters, holding a standard automatic as well as a terribly destructive flame pistol. He whipped it around him, seized another bundle, and plunged into the eternal mists of Uranus.
It was exactly as if he stood under an inverted bowl of dull silver. A weird, greenish, half twilight filtered down, but his whole world consisted of the metal ship at his back and a fifty-foot semicircle before him. And Pat—Pat was nowhere visible.
He shouted her name. "Pat!" The sound muffled by the cold dampness of the fog sounded queerly soft to his ears. He bellowed again at the top of his voice, and then swore violently from sheer relief as a thin, hushed reply drifted back out of the grayness.
In a moment she appeared, swinging a zigzag, ropy, greenish-gray organism.
"Look!" she called triumphantly. "Here's the first specimen of Uranian plant life. Loosely organized, reproduces by partition, and—what the devil is the matter?"
"Matter! Don't you know you might have been lost? How did you expect to get back here?"
"Compass," she retorted coolly.
"How do you know it works? We may be right on the magnetic pole, if Uranus has one."
She glanced at her wrist. "Come to think of it, it doesn't work. The needle's swinging free."
"Yes, and you went out unarmed besides. Of all the fool tricks!"
"Young reported no animal life, didn't he? And—wait a minute. I know what you're going to say. `Forty-five thousand miles away!' "
He glared. "Hereafter," he growled, "you're under orders. You don't go out except in company, and roped together." He drew a length of heavy silken cord from his pocket, and snapped one end to her belt, and the other to his own.
"Oh, don't be so timid! I feel like a puppy on a leash."
"I have to be timid," he responded grimly, "when I'm dealing with a reckless, improvident, careless imp like you."
He disregarded her sniff of disapproval, and set about unwrapping the bundle he had brought. He produced an American flag, and proceeded to dig a depression in the gravel, planted the staff in it and said formally, "I take possession of this land in the name of the United States of America."
"All fifty feet of it?" murmured Patricia, but softly, for, after all, despite her flippant manner, she was loyal to the country of her husband. She fell silent, and the two of them stared at the flag.
It was a strange echo from a pleasant little planet nearly two billion miles away; it meant people and friends and civilization—things remote and almost unreal as they stood here on the soil of this vast, lonely, mysterious planet.
Ham roused from his thoughts. "So!" he said. "Now we'll have a look around."
Young had indicated the technique of exploration on this world where the explorer faced difficulties all but insurmountable.
Ham snapped the end of a fine steel wire to a catch beside the air lock. On a spool at his waist was a thousand foot length of it, to serve as an infallible guide back through the obscurity—the only practical means in a region where sound was muffled and even radio waves were shielded almost as completely as by a grounded metal dome. The wire played the part not only of guide but of messenger, since a tug on it rang a bell within the rocket.
Ham waved at Harbord, visibly puffing his pipe behind the port, and they set out. To the limit of their permitted time, Uranus would have to be explored in thousand-foot circles, moving the rocket each time the details of the area were recorded. A colossal task. It was likely, he remarked to Pat, that the vast planet would never be completely explored, especially with the forty-year interval that must pass between visits.
"And especially," she amended, "if they send timorous little better-be- safe-than-sorry explorers like you."
"At least," he retorted, "I expect to return to tell what I've explored even if it's only a myriare, like Young's achievement."
"But don't you see," she rejoined impatiently, "that wherever we go, just beyond our vision there may be something marvelous? We take little thousand- foot samples of the country, and each time we might be just missing something that may be the whole significance of this planet. What we're doing is like marking off a few hundred-foot circles on the Earth; how much chance is there of finding part of a city, or a house, or even a human being in our circle?"
"Perfectly true, Pat, but what can we do about it?"
"We could at least sacrifice a few precautions and cover a little more territory."
"But we won't. I happen to care about your safety."
"Oh!" she said irritably, turning away. "You're—" Her words were muffled as she ranged out to the full length of the silken cord that bound her to him. She was completely invisible, but occasional jerks and tugs as they tried to move at cross-purposes were evidence enough that they were still joined.
Ham walked slowly forward, examining the pebbled, lifeless terrain where now and then a pool of condensed moisture showed dull, and very occasionally, he came upon one of the zigzag weeds like the one Pat had dropped near the rocket. Apparently rain was unknown on windless Uranus, and the surface moisture followed an endless cycle of condensation in the cool air and evaporation on the warm ground.
Ham came to a spot where boiling mud seemed to be welling up from below, and steamy plumes whirled up to lose themselves in the fog—evidence of the vast internal heat that warmed the planet. He stood staring at it, and suddenly a violent jerk on the cord nearly toppled him backward.
He spun around. Patricia materialized abruptly out of the fog, one hand clutching a ropy plant. She dropped it as she saw him, and suddenly she was clinging frantically to him.
"Ham!" she gasped. "Let's go back! I'm scared!"
"Scared? Of what?" He knew her character; she was valiant to the point of recklessness against any danger she could under-stand, but let there be a hint of mystery in an occurrence, and her active imagination painted horrors beyond her ability to face.
"I don't know!" she panted. "I—I saw things!"
"In the fog! Everywhere!"
Ham disengaged his arms and dropped his hands to the butts of the weapons in his belt. "What sort of things?" he asked. "Horrible things! Nightmarish things!"
He shook her gently. "Who's timid now?" he asked, but kindly. The query had the effect he sought; she gripped herself and calmed.
"I'm not frightened!" she snapped. "I was startled. I saw—" She paled again.
"I don't know. Shapes in the mist. Great moving things with faces. Gargoyles—devils—nightmares!" She shuddered, then calmed once more.
"I was bending over a little pool out there, examining a biopod, and everything was quiet—sort of deadly quiet. And then a shadow passed in the pool—a reflection of something over me—and I looked up and saw nothing. But then I began to hear rustles and murmurs and noises like muffled voices and I began to see the fog shapes—horrible shapes—all around me. And I screamed, and then realized you couldn't hear a scream, so I jerked the rope. And then I guess I just closed my eyes and rushed through them to you." She shivered against him.
"All around you?" he asked sharply. "Do you mean between you and me?"
She nodded. "Everywhere."
Ham laughed shortly. "You've had a day dream, Pat. The rope isn't long enough for anything to pass between us without coming so close to one of us that he could see it clearly, and I saw nothing—absolutely nothing."
"Well, I saw something," she insisted, "and it wasn't imaginary. Do you think I'm just a nervous child afraid of strange places? Why I was born on an alien planet!" At his indulgent grin she flared in indignation. "All right! Let's both of us stand here perfectly quiet; perhaps they'll come back again; then we'll see what you think of them."
He nodded agreement, and they stood silently under the translucent dome of mist. There was nothing, nothing but a deep and endless grayness, and an infinite silence, but a silence not like any Ham had ever experienced in his life. For on Venus —even in the sultriest part of the Hotlands—there is always the rustle of teeming life, and the eternal moaning of the underwind, while on the Earth no day nor night is ever quite silent.
There is always somewhere the sighing of leaves or the rustle of grass or the murmur of water or the voices of insects, or even in the driest desert, the whisper of sand as it warms or cools. But not here; here was such utter stillness that the girl's breathing beside him was an actual relief; it was a silence utter enough to hear.
He did hear it—or was it simply his own blood pulsing in his ears? A formless throbbing, an infinitely faint rustling, a vague whispering. He frowned in the concentration of listening, and Patricia quivered against him.
"There!" she hissed. "There!"
He peered into the gray dimness. Nothing at all—or was there something? A shadow—but what here could cause a shad-ow, here in this sunless region of fog? A condensation of mist, that was all. But it moved; mist can't move without the thrust of wind, and here there was no wind.
He strained his eyes in an effort to pierce the obscurity. He saw—or he imagined it—a vast, looming figure, or a dozen figures. They were all around; one passed silently overhead, and numberless others weaved and swayed just beyond the range of vision. There were murmurings and susurrations, sounds like breathing and whispering, patters and rustles. The fog shapes were weirdly unstable, looming from little patches of darkness into towering shadows, dissipating and forming like figures of smoke.
"Good Lord!" gasped Ham. "What can—"
He tried to focus his gaze on one individual in the shadowy throng. It was difficult; they all seemed to shift, to merge, advance, recede, or simply materialize and fade out. But one surprising phenomenon suddenly caught his attention, and for a moment stunned him into rigidity. He saw faces!
Not exactly human faces. They were more such appearances as Patricia had described—the faces of gargoyles or devils, leering, grimacing, grinning in lunatic mirth or seeming to weep in mockery of sorrow. One couldn't see them clearly enough for anything but fleeting impressions—so vague and instantaneous that they had the qualities of an illusion or dream.
They must be illusions, he thought confusedly, if only because their conformation, though not human, imitated the human. It was beyond the bounds of reason to suppose that Uranus harbored a race of humans, or even humanlike beings.
Beside him Patricia whimpered, "Let's go back, Ham. Please let's go back."
"Listen," he said, "those things are illusory, at least in part."
"How do you know?"
"Because they're anthropomorphic. There can't be any creatures here with nearly human faces. Our own minds are adding details that don't exist, just as every time you see a cloud or a crack on the ceiling you try to make a face out of it. All we're seeing is denser spots in the mist."
"I wish I thought you were sure of that," she quavered.
He wasn't at all sure, but he reaffirmed it. "Of course I am. I'll tell you an easy way to prove it, too. We'll turn the infra-red camera on them, and that'll bring out enough detail to judge by."
"I'd be afraid to look at the plates," said the girl, shivering as she peered apprehensively at the vague horrors in the fog. "Suppose—suppose they do show those faces. What will you say then?"
"I'll say that it's a queer and unexpected coincidence that Uranian life—if they are forms of life—has developed along somewhat the same lines as terrestrial—at least in outward form."
"And you'll be wrong," she murmured. "A thing like this is beyond coincidence." She trembled against him. "Do you know what I think? Ham, do you suppose it's possible that science has gone all wrong, and that Uranus is Hell? And that those are the damned?"
He laughed, but even his laugh sounded hollow, muffled by the smothering fog. "That's the maddest idea that even your wild imagination has ever produced, Pat. I tell you they're—"
A scream from the girl interrupted him. They had been standing huddled together, staring at divergent angles into the dome of mist, and he spun around now to gaze in the direction she faced.
For a moment his vision was blinded by the shift, and he blinked frantically in an effort to focus his eyes. Then he saw what had startled her. It was a vast, dusky shadow that seemed to originate somewhere near the surface, but was springing up-ward and curving over them as if it actually climbed a veritable dome of mist, like a dim river of darkness flowing upward.
Despite his derision of Patricia's fear-born imaginings, his nerves were taut. It was a purely automatic gesture that brought his weapon to his hand, and it was pure impulse that sent a bullet flaming into the mist. There was a curiously muffled report from the shot—a single full echo—and then utter silence.
Utter silence. The rustles and murmurings were gone—and so were the fog-shapes. Blinking into the mist, they saw only the sullen grayness of the eternal cloud itself, and they heard no sound but their own tense breathing and the faint after-ring of their eardrums from the concussion.
"They're gone!" the girl gasped.
"Sure. Just what I said. Illusions!"
"Illusions don't run away from gunshots," retorted Patricia, her courage revived instantly with the vanishing of the fog shapes. "They're real. I'm not nearly as afraid of real things as of—well, of things I can't understand."
"Do you understand these?" he rejoined. "And as for illusions not running away from gunshots, I say they might. Suppose these appearances were due to a sort of self-hypnosis, or even merely to the eye strain of staring through this fog. Don't you think a shot would startle us out of the proper mental state, so that we'd no longer see them?"
"Maybe," she said doubtfully. "Anyway, I'm not scared any more. Whatever they are, I guess they're harmless."
She turned her attention to the puddle of mud before them, in which a few curious feathery growths swayed to the bubbling of the surface. "Cryptogamoid," she said, stooping over them. "Probably the only sort of plant that can exist on Uranus, since there's no sign of bees, or other pollen carriers."
Ham grunted, peering into the dismal gray mist. Suddenly both of them were startled into sudden alertness by the sound of the bell on the drum that held the guide wire. One ring; a warning from the Gaea!
Pat sprang erect. Ham tugged the wire in instant reply, and muttered, "We'd better go back. Harbord and Cullen must have seen something. It's probably the same sort of things we saw, but we'd better go back."
They began to retrace their steps, the thousand feet of wire humming softly as it wound back on the spring drum at Ham's waist. Other than that and the crunch of their steps on the gravel, there was silence, and the fog was merely a featureless dome of faintly greenish grayness. They had progressed perhaps two hundred yards when it changed.
Patricia saw the fog shapes first. "They're back!" she hissed in his ear, with no sound of fear in her voice now.
He saw them too. Now they were no longer surrounding the two of them, but were rushing past from the direction of the Gaea in two parallel streams, or perhaps dividing into two streams just beyond the point of visibility. He and Pat were moving down an alley walled by a continuous double line of rushing shadows.
They huddled closer to each other and bored on through the fog. They were no more than a hundred and fifty feet from the rocket now. And then, with a suddenness that brought them to a sharp halt, something more solid than fog, more solid than fog shapes, loomed darkly straight before them.
It—whatever it was—was approaching. It was visible now as a dark circle at the level of the ground, perhaps six feet in diameter, upright and broadside on. It was moving as fast as a man walks, and it materialized rapidly into a distinct solidity.
Ham and Pat stared fascinated. The thing was featureless—just a dull black circle and a tubular body that stretched off into the fog. Or not quite featureless. Now they could perceive an organ that projected from the center of the circle—a loose, quivering member like a large pancake on a finger-thick stem, whose edges quivered and cupped toward them, as if to catch sounds or scent. The creature was blind.
Yet it possessed some sense that could register distant objects. Thirty feet from them the stalked disc cupped deeply in their direction, the creature swerved slightly, and rushed silently toward the pair!
Ham was ready. His automatic roared its muffled blast, and roared again. The attacker seemed to telescope in upon itself and rolled aside, and behind it appeared a creature identical in all respects—the same featureless black circle, the same quivering disc. But a high, piercing whine of pain slipped like a sharp knife through the fog.
This was a danger Patricia could understand. There was no fear about her now; she had faced too many outlandish creatures on the Hotlands frontiers of Venus, or in the mysterious wilds of the Mountains of Eternity.
She snatched her companion's flame pistol from its holster and stood with the weapon ready to vomit its single blast of destruction. She knew that it represented a last resort, not to be used until other means had failed, so she simply held it, and tugged on the wire to the Gaea. Three pulls, and then again three, would summon aid from Cullen and Harbord.
The second creature—or was it another segment of the same animal?—came charging forward. Ham sent two more bullets into the blank, faceless front of it, and again that keening note of pain sounded. The monster swerved and collapsed, and another black circle was rushing toward them. His shot failed to drop this one, but the creature veered.
Suddenly the thing was roaring past them, black and huge as a railroad train. It was a segmented being; it was composed of dozens of eight-foot links, like a train of miniature cars, three pairs of legs to a section.
But it ran like a single creature, with ripples of motion flowing back along its countless legs in exactly the way a centipede runs. Ham had a flashing glimpse of the manner in which the segments were joined by finger- thick ropes of flesh.
He sent three bullets into the middle of a passing section. It was a bad mistake; the segment spouted black liquid and rolled out of line, but the one behind it suddenly turned its stalked member toward the two defenders and came rushing at them. And off in the fog the first section was circling back. They had two to face now instead of one.
Ham had three cartridges left in the clip. He grimly fired one shot full at the quivering disc of flesh that cupped toward him, saw the monster collapse, and sent another bullet into the segment that followed. The thing—or things—seemed to extend indefinitely into the fog.
Beside him he heard the roar of the flame pistol. Pat had waited until the other monster was nearly upon her, so that her single blast might do as much damage as possible.
Ham stole time for a momentary glance at the result; the terrific discharge had simply incinerated a dozen segments, and one solitary survivor was crawling away into the fog.
"Good girl!" he muttered and sent his last bullet into the on-rushing monstrosity. It dropped, and behind it, driving inexorably on, came the follower. He flung his empty weapon at the fleshy disc, saw it bound off the black skin, and waited, thrusting Pat behind him.
There was a great, roaring light. A flame pistol! Dim in the fog were the figures of Harbord and Cullen, tracing their way along the wire, and before him were writhing segments of the blasted monster.
What remained of the creature had had enough punishment, apparently, for it veered to the left and went thundering away into the mist, now no more than ten segments long. And all around the group, just beyond visibility, the fog shapes gestured and grimaced and gibbered, and then they too vanished.
Not a word was spoken as the four traced the wire to the door of the Gaea. Once within, Patricia let out a low whistle of relief as she pulled off her dripping jacket. "Well," she breathed. "That was a thrill."
"A thrill!" snorted Ham. "Say, you can have this whole soggy planet for all of me. And I've a mind to limit you to the ship, too. This is no place for a thoughtless imp like you; you draw trouble the way honey draws flies."
"As if I had anything to do with it!" she retorted. "All right; order me to stay aboard if you think it'll do any good."
He grunted and turned to Harbord. "Thanks," he said.
"That was close until you two showed up. And by the way, what was the warning for? The fog shapes?"
"Do you mean that Mardi Gras parade that's been going by?" asked Harbord. "Or was it a spiritualist convention? No; we weren't sure they were real. It was for the thing you did get tangled up with; it came humping by here in your direction."
"It or they?" corrected Ham.
"Did you see more'n one of them?"
"I made more than one of them. I cut it in half, and both halves went for us. Pat took care of one with the flame pistol, but all my bullets seemed to do was to knock off pieces." He frowned. "Do you understand the thing, Pat?"
"Better than you do," she retorted sharply. His threat to restrain her to the ship still rankled. "This would be a fine expedition without a biologist, wouldn't it?"
"That's the reason I'm being careful about von," he grinned. "I'm afraid I would be without a biologist. But what's your idea concerning that series of detachable worms out there?"
"Just that. It's a multiple animal. Did you ever hear of Henri Fabre?"
"Not that I remember."
"Well, he was a great French naturalist of about two centuries ago. Among other things, he studied some interesting little insects called processionary caterpillars, who spin themselves a cozy nest of silk and march out of it every night to feed."
"Just listen a moment," said the girl. "They march out single file, every caterpillar touching its head to the tail of the one preceding it. They're blind, you see; so each one trusts the one ahead. The first one's the leader; he picks the route, leads them to the proper tree, and there the column breaks up for feeding. And at sunrise, they form again into little columns, which join again into the big procession, and back they go to their nest."
"I still don't see—"
"You will. Now, whichever caterpillar is in front is the leader. If you take a stick and break the column at any point, the one behind the gap becomes the leader for his followers, and leads them back to the cobweb nest just as efficiently as the original leader. And if you segregate any one caterpillar, he finds his own way, being leader and column in one."
"I begin to see," muttered Ham.
"Yes. That think or those things—are something like the processionary caterpillars. They're blind; in fact, eyes would have much less value on Uranus than on the Earth, and perhaps no Uranian creatures developed eyes—unless the fog shapes possess them. But I think these creatures are a long way ahead of processionaries, because the caterpillars establish their contact along a thread of silk, but these fellows, apparently, do it through actual nerve ganglia."
"Eh?" queried Ham.
"Of course. Didn't you notice how they were joined? That flat organ in front—each one had it slapped like a sucking disc against the one before him—was always placed in identically the same position. And when you shot one out of the middle of the file, I saw the pulpy lump it had covered on the one it followed. And besides—" She paused.
"Well, didn't it strike you as strange that the whole line cooperated so well? Their legs moved in a sort of rhythm, like the legs of a single creature, like the legs of a myriapod—a centipede.
"I don't think habit or training or discipline could ever account for the way that file of creatures acted, rushing and stop-ping and veering and circling, all in perfect unison. The whole line must have been under the direct neutral control of the leader—hearing and smelling what he heard and smelled, even, perhaps, responding to his desires, hating with him and finally fearing with him!"
"Damned if I don't think you're right!" exclaimed Ham. "The whole bunch of them acted like one animal!"
"Until you carelessly created two by breaking the line," corrected the girl. "You see—"
"I made another leader!" finished Ham excitedly. "The one behind the break in the file became a second leader, able to act independently." He frowned. "Say, do you suppose those things accumulate their intelligence when they join? Does each one add his reasoning power—if any—to the dominating brain of the leader?"
"I doubt it," said the girl. "If that were true, they would be able to build up a colossal intellect just by adding more sections. No matter how stupid each individual might be, they'd only have to click together enough of them to create a godlike intelligence.
"If anything like that existed here, or ever had existed, they wouldn't be rushing around weaponless and savage. There'd be some sort of civilization, wouldn't there? But," she added, "they might pool their experience. The leader might have all the individual memories at his disposal, which wouldn't add a darn thing to his reasoning powers."
"Sounds plausible," agreed Ham. "Now as to the fog shapes. Have you figured out anything about them?"
She shuddered. "Not much," she confessed. "I think there's a relationship between them and these others, though."
"Because they came streaming by us just before the attack. They might simply have been running away from the multiple creature, but in that case they ought to have scattered. They didn't; they came rushing by in two distinct streams, and not only that, but all during the fight they were flickering and shimmering in the background. Didn't you notice that?"
"My attention was occupied," replied Ham dryly. "But what about it?"
"Well, did you ever hear of the indicator albirostris—the honey- guide?"
"It sounds vaguely familiar."
"It's an African bird of the cuckoo family, and it guides human beings to the wild bee colonies. Then the man gets the honey and the bird gets the grubs." She paused. "I think," she concluded, "that the fog shapes played honey-guide to the others. I think they led the creatures to us either because your shot angered them, or because they wanted the leavings after the others were through with us, or because they're just plain destructive. Anyway, that's my guess."
"If they're real," added Ham. "We'll have to turn the infra-red camera on the next group or herd or swarm or flock, or what-ever you call their gatherings. I still think they're mostly illusory."
She shuddered. "I hope you're right," she murmured.
"Bah!" said Harbord suddenly. "Women don't belong in places like this. Too timid."
"Yeah?" retorted Ham, now fully prepared to defend Patricia. "She was cool enough to notice details during that fracas out there."
"But afraid of shadows!" grumbled Harbord.
However, they weren't shadows. Some hours later Cullen reported that the fog around the Gaea was full of shifting, skittering shapes, and he trundled the long-wave camera from port to port.
Handicapped by the argon-laden air with its absorption spectrum that filtered out long rays, the infra-red plates were nevertheless more sensitive than the human eye, though perhaps less responsive to detail. But a photographic plate is not amenable to suggestion; it never colors what it sees by the tint of past experience; it records coldly and unemotionally the exact pattern of the light rays that strike it.
When Cullen was ready to develop his plates, Patricia was still asleep, tired out by the hectic first day on the planet, but Ham came out drowsily to watch the results.
These might have been less than she feared, but they were more than Ham expected. He squinted through a negative toward the light, then took a sheaf of prints from Cullen, frowning down at them.
"Humph!" he muttered. The prints showed something, beyond doubt, but something not much more definite than the unaided eye had seen. Indubitably the fog shapes were real, but it was equally certain that they weren't anthropomorphic.
The demoniac faces, the leering visages, the sardonic countenances, were decidedly absent to the eye of the camera; to that extent the beings they had seen were illusions, whose features had been superimposed by their own minds on the shadows in the fog. But only to that extent, for behind the illusion lay something unmistakably real. Yet what physical forms could achieve that flickering and shifting and change of shape and size that they had observed?
"Don't let Pat see these unless she asks to," he said thoughtfully. "And I think I'll confine her to the ship for the present. Judging from the couple of acres we've seen so far, this place isn't the friendliest sort of locality."
But he figured without the girl on both counts. When, fifteen hours later, he moved the rocket a mile south and prepared for another circuit in the fog, she met his order with a storm of protest.
"What's this expedition for?" she demanded. "The most important thing on a planet is the life it supports, and that's a biologist's business, isn't it?"
She turned indignant eyes on Ham. "Why do you think the Institute chose me for this job? Just to sit idly in the rocket while a couple of incompetents look around—a chemist and an engineer who don't know an epiphyte from a hemipteron?"
"Well, we could bring in specimens," muttered Ham miserably.
That brought a renewed storm. "Listen to me!" she snapped. "If you want the truth, I'm not here because of you. You're here because of me! They could have found a hundred engineers and chemists and astrogators, but how many good extraterrestrial biologists? Darn few!"
Ham had no ready reply, for it was quite true. Despite her youth, Patricia, born on Venus and educated in Paris, was admittedly preeminent in her field. Nor, in all fairness to the backers of the expedition, could he handicap her in her work. After all, not even the government-financed Smithsonian could afford to spend somewhat over two million dollars without getting fair return for its money.
Sending a rocket out into the depths where Uranus plowed its lonely orbit was a project so expensive that in simple justice the expedition had to do its utmost, especially since forty long years would elapse before there would be another opportunity to visit the doubtful planet. So he sighed and yielded.
"That shows a faint glimmering of intelligence," said Patricia. "Do you think I'm afraid of some animated links of sausages? I won't make the mistake of cutting them in the middle. And as for those funny-faced shadows, you said yourself that they were illusions, and—by the way, where are the pictures you were going to take of them? Did they show anything?"
Cullen hesitated, then at Ham's resigned nod, he passed her the sheaf of prints. At the first glance she frowned suddenly.
"They're real!" she said, and then bent over them with so intent an expression that Ham wondered what she could read from so vague and shadowy a record. He saw, or fancied he saw, a queer gleam of satisfaction in her eyes, and felt a sensation of relief that at least she wasn't upset by the discovery.
"What d'you make of them?" he asked curiously. She smiled and made no answer.
Apparently Ham's fears concerning Patricia were ill-founded on all counts. The days passed uneventfully; Cullen analyzed and filed his samples, and took innumerable tests of the greenish Uranian atmosphere; Ham checked and rechecked his standard weights, and in spare moments examined the reaction motor on which the Gaea and their lives depended; and Patricia collected and classified her specimens without the least untoward incident.
Harbord, of course, had nothing to do until the rocket plunged once more into the vastness of space, so he served as cook and general utility man—an easy enough task consisting largely of opening cans and disposing of the debris.
Four times the Gaea soared aloft, picked her way through the eternal mists to a new station, and settled down while Ham and Patricia explored another thousand-foot circle. And somewhere in the grayness above, forever invisible, Saturn swung into conjunction, passed the slower-moving Uranus, and began to recede. Time was growing short; every hour meant additional distance to cover on the return.
On the fifth shift of position, Harbord announced the limit of their stay. "Not more than fifty hours more," he warned, "unless you have an inclination to spend the next forty years here."
"Well, it's not much worse than London," observed Ham, pulling on his outdoor clothing. "Come on, Pat. This'll be our last look at the pleasant Uranian landscape."
She followed him into the gray open, waiting while he clicked his guide wire to the rocket, and the silken rope to her belt. "I'd like to get one more look at our chain-gang friends," she complained. "I have an idea, and I'd like to investigate it."
"And I hope you don't," he grunted. "One look was plenty for me."
The Gaea disappeared in the eternal mist. Around them the fog shapes flickered and grimaced as they had done ever since that first appearance, but neither of them paid any attention now. Familiarity had removed any trace of fear.
This was a region of small stony hillocks, and Patricia ranged back and forth at the full length of the rope, culling, examining, discarding, or preserving the rare Uranian flora. Most of the time she was beyond sight or sound, but the cord that joined them gave evidence of her safety.
Ham tugged impatiently. "Like leading a puppy past a row of trees," he growled as she appeared. "Wire's end!" he called. "We'll circle back."
"But there's something beyond!" she cried. By virtue of the rope she could range an additional fifty feet into the obscurity. "There's something growing just out of reach there—something new! I want to see it."
"Hell, you can't. It's out of reach and that's that. We can lengthen the wire a little and come back for it."
"Oh, it's just a few feet." She turned away. "I'll release the rope, take a look, and come back."
"You won't!" he roared. "Pat! Come here!"
He tugged mightily on the rope. A faint exclamation of disgust drifted out of the dimness, and then, suddenly, the rope came free in his hands. She had freed herself!
"Pat!" he bellowed. "Come back! Come back, I say!"
A smothered reply sounded, all but inaudible. Then there was utter silence. He shouted again. The all-enveloping fog muffled his voice in his own ears. He waited a moment, then repeated his call. Nothing; no sound but the rustle of the fog shapes.
He was in a desperate quandary. After another pause he fired his revolver into the air, all ten shots at brief intervals. He waited, then fired another clip without response from the passive, leaden-hued fog. He swore bitterly at the girl's foolhardiness, at his own helplessness, and at the grimacing fog shapes.
He had to do something. Go back to the Gaea and set Harbord and Cullen searching. That wasted precious time; every moment Patricia might be wandering blindly away. He muttered a phrase that might have been either an imprecation or a prayer, pulled a pencil and a piece of paper from his pocket, and scrawled a message: "Pat lost. Bring additional spool and attach to wire. Circle for me. Will try to stay within two-thousand-foot radius."
He clipped the paper to the wire's end, weighted it with a stone, and then tugged three times to summon the two from the Gaea. Then he deliberately released himself and plunged unguided into the fog.
He never knew how far or how long he walked. The fog shapes gibbered and mocked him, the condensation gathered on his face and dripped from his nose and chin, the fog pressed in about him. He shouted, he fired his automatic, he whistled, hoping that the shriller sounds might carry, he zigzagged back and forth across his route. Surely, he thought, Pat had sense enough not to wander. Surely a girl trained in the Hotlands of Venus knew that the proper procedure when lost was to remain still, lest one stray still farther from safety.
Ham himself was utterly lost now. He had no faintest conception of where the Gaea lay, nor in what direction was the guiding wire. Now and again he thought he spied the silver filament of safety, but each time it was only the glint of water or the dull sparkle of stone. He moved under on inverted bowl of fog that blocked off vision on every hand.
In the end it was the very weakness of the lost that saved him. After hours of hopeless plunging through the mist, he tripped—actually tripped—over the wire. He had circled.
Cullen and Harbord loomed suddenly beside him, joined by a silken rope. He gasped. "Have you—have you—"
"No," said Harbord gloomily, his lined visage looking bleak and worn. "But we will. We will."
"Say," said Cullen, "why don't you go aboard and rest up? You look about done in, and we can carry on for you." "No," said Ham grimly.
Harbord was unexpectedly gentle. "Don't worry," he said. "She's a sensible sort. She'll stay put until we find her. She can't have wandered a full thousand feet beyond the wire's end."
"Unless," responded Ham miserably, "she was driven—or carried."
"We'll find her," repeated Harbord.
But ten hours later, after they had completely circled the Gaea at a dozen different distances, it became obvious that Patricia was not within the circumference described by their two-thousand-foot wire. Fifty times during the intolerable circuit Ham had fought against the impulse to free himself of the wire, to probe just a little farther into the tantalizing fog.
She might be sitting despondently just beyond sight and ear-shot, or she might be lying injured within an easy stone's throw of the circle, and they'd never know it. Yet to release himself from the one guide that marked their base was little better than suicide and somewhat more than sheer insanity.
When they reached the stake that Cullen had driven to mark their starting point, Ham paused. "Back to the ship," he ordered grimly. "We'll move her four thousand feet in this direction and circle again. Pat can't have wandered a mile from the point I lost her."
"We'll find her," reiterated Harbord.
But they didn't find her. After a futile, exhausting search, Ham ordered the Gaea to a point at which their wirebound circle was tangent to the two circles already explored, and grimly began again.
Thirty-one hours had passed since the girl had disappeared, and the three were nearing exhaustion. It was Cullen who yielded first, and groped his way wearily back to the ship. When the other two returned to move to a new base, they found him sleeping fully clothed beside a half-drained cup of coffee.
The hours dropped slowly into eternity. Saturn was pulling steadily ahead of the misty planet, bound placidly for their next meeting forty years in the future. Harbord said not a word concerning the passing of time; it was Ham who broached the subject.
"Look here," he said as the Gaea slanted down to a new position. "Time's short. I don't want you two marooned here, and if we don't find Pat in this area, I want you and Cullen to leave. Do you understand?"
"I understand English," said Harbord, "but not that sort."
"There's no reason for you two to stay. I'm staying. I'll take our portion of food and all the arms and ammunition, and I'll stay."
"Bah!" growled Harbord. "What's forty years?" He had turned sixty.
"I'm ordering you to leave," said Ham quietly.
"You don't command once we're clear of the surface," grunted the other. "We're staying. We'll find her."
But it began to seem utterly hopeless. Cullen awoke and joined them as they emerged into the infinite fog, and they took their places at six hundred and sixty foot intervals along the wire. Ham took the outermost position and they began their endless plodding through the mists.
He was close to the breaking point. For forty hours he had neither slept nor eaten, save for a hurried gulp of coffee and a bite of chocolate when they moved the Gaea. The fog shapes were beginning to take the weirdest conformations in his tired eyes, and they seemed to loom ever closer, and to grin more malevolently.
So it was that he had to blink and squint and peer very closely when, a quarter way around the circuit, he saw something a little denser than the fog shapes in the gloom.
He jerked the wire once to halt Harbord and Cullen, and stared fixedly. There was a sound, too—a faint, steady thrumming quite different from the eerie rustles of the fog shapes. He started sharply as he heard still another sound, indescribable, muffled, but certainly a physical sound. He jerked the wire three times; that would summon his companions.
They came, and he pointed out the dusky mass. "We can reach it," he suggested, "if we tie a couple of our ropes together. Two should be plenty."
They moved cautiously into the mist. Something—something was stirring there. They crept quietly on, fifty feet, sixty. And suddenly Ham realized that he saw a chain of the multiple creatures—a vast chain, apparently, for it was still passing before them. In utter despondency he stopped, staring hopelessly ahead; then, very slowly, he turned back toward the wire.
A sound—a sharp sound—froze him. It sounded like a cough!
He whirled back. Regardless of the dangerous file close be-fore him, he shouted. "Pat! Pat!"
The sublimity of relief! A thin little voice quavered beyond the line. "Ham! Oh, Ham!"
"Are—you—are you safe?"
He was at the very side of the passing file. Beyond, pale as the mist itself, was Patricia, no more than ten feet away.
"Thank God!" he muttered. "Pat, when this chain passes, run straight here. Don't move a single step aside—not a single step!"
"Passes?" she quavered. "Oh, it won't pass! It isn't a file. It's a circle!"
"A circle!" Comprehension dawned. "A circle! Then how—how can we get you out? We can't break it or—" He paused. Now the queer parade was leaderless, helpless, but once it were broken at any point, it would turn into a fierce and bloodthirsty thing—and it might attack the girl. "Lord!" he gasped.
Harbord and Cullen were beside him. "Here!" he snapped. He seized the remaining rope. "I'm going across. Stand close."
He crawled to the shoulders of the two. From that height it might be possible to leap the creatures. It had to be possible.
He made it, though it left Cullen and Harbord groaning from the thrust of his hundred and eighty pounds, Uranus weight. He spent only a moment holding Patricia to him; the menace of those circling monsters was too imminent.
He flung an end of the rope to the two beyond the circle. "Can you swing across if we hold it high enough, Pat?" The girl seemed on the verge of exhaustion.
"Of course," she murmured.
He helped her lock elbows and knees around the rope. Slowly, painfully, she inched her way in the manner of a South American tree sloth. Ham had one terrible instant of fear as she wavered directly over the file, but she made it, dropping weakly into Harbord's arms beyond.
Then she cried out, "Ham! How can you get across?"
"Vault 'em!" he flashed.
He spent no time in reflection. He gathered all the strength remaining in his body, drew back for a short run, and actually cleared the six-foot barrier of deadliness, his knuckles just touching a black, blubbery back.
Patricia struggled to her feet, clinging to him. He held her a moment, then said huskily, "Lord! If we hadn't found you—"
"But you did!" she whispered. Suddenly she began to laugh hysterically, the sound broken by choking coughs. "Only what kept you? I expected you sooner!" She stared wildly at the circling file. "I short-circuited them!" she cried. "I—short-circuited —their brains!"
She collapsed against him. Without a word he lifted her and followed Harbord and Cullen back along the wire to the Gaea. Behind him, revolving endlessly, was the circle of doomed creatures.
Uranus was a banded green globe behind the flare of the afterjets, and Saturn a brilliant blue star to the left of a tiny, very fierce sun. Patricia, her cough already improved in the conditioned air of the Gaea, lay passively in a pivot chair and smiled at Ham.
"You see," she said, "after I cast off the rope—Wait! Don't lecture me again about that!—I stepped just the merest few paces into the fog, and then, after all, the plants I had seen turned out to be the same old zigzag ones I named Cryptogami Urani, so I started back and you were gone."
"Gone! I hadn't moved."
"You were gone," she repeated imperturbably. "I walked a short distance and then shouted, but the shouts just sort of muffled out. And then I heard a couple of shots in another direction, and started that way—and suddenly the chain gang came plunging out of the fog!"
"What'd you do?"
"What could I do? They were too close for me to draw my gun, so I ran. They're fast, but so am I, and I kept ahead until I began to lose breath. Then I discovered that by sharp dodging I could keep away—they don't turn very quickly—and I managed for a few minutes, although that blinding fog kept me in danger of tripping. And then I had an inspiration!"
"You needed one!" he muttered.
She ignored him. "Do you remember when I mentioned Fabre and his studies of the pine processionary caterpillars? Well, one of his experiments was to lead the procession around the edge of a big garden vase and close the circle! He did away with the leader, and do you know what happened?"
"I can guess."
"You're right. Lacking leadership, the circle just kept revolving for hours, days, I don't know how long, until at last some caterpillar dropped from exhaustion, and a new leader was created by the gap. And suddenly that experiment occurred to-me, and I set about duplicating it. I dodged back toward the rear end of my procession, with the front end following me!"
"I see!" muttered Ham.
"Yes. I intended to close the circle and dodge outside, but something went wrong. I caught up with the rear all right, but I was just about worn out and I stumbled or something, and the next thing I remember was lying on the ground with the feet of the things pounding by my face. And I was inside the circle!"
"You probably fainted from exhaustion."
"I never faint," said Patricia with dignity.
"You did when I got you out."
"That," she retorted, "was simply a case of going to sleep after about forty hours of staying awake without food. Fainting, or syncope, is quite different, being due to an undersupply of blood to the brain—"
"All right," cut in Ham. "If fainting needs a brain, obviously you couldn't faint. Go on."
"Well," she resumed placidly, "there I was. I could have shot a break in the circle, of course, but that would have brought an attack, and besides, I hadn't the least idea where the Gaea was. So I sat there, and I sat a week or ten days or a month—"
"And the fog shapes kept rustling over the file of sausage creatures, and they kept flickering and rustling and whispering until I thought I'd go mad. It was terrible—even knowing what they were, it was terrible!"
"Knowing what— Do you know what they are?"
"I figured out one good guess. In fact, I had a suspicion as soon as I saw Cullen's infra-red photographs."
"Then what the devil are they?"
"Well, you see I had a good chance to examine the chain things at close range, and they're not perfect creatures."
"I'll say they're not!"
"I mean they're not fully developed. In fact, they're larvae. And I think the fog shapes are what they grow up to be. That's why the fog shapes led the things to us. Don't you see? The chain creatures are their children. It's like caterpillar and moth!"
"Well, that's possible, of course, but what about the weird faces of the fog shapes, and their ability to change size?"
"They don't change size. See here—the light on that part of Uranus comes from directly overhead, doesn't it? Well, any shadows are thrown straight down, then; that's obvious. So what we saw—all that flickering, shifting crew of gargoyles—were just the shadows of floating things, flying things, projected on the fog. That's why the fog shapes grew and shrank and changed shape; they were just shadows following some winged creature that moved up and down and around. Do you see?"
"It sounds plausible. We'll report it that way, and in eighty years, when the north pole part of Uranus gets around to the Sunlight again, somebody can run up and check the theory. Maybe Harbord'll pilot them. Eh, Harbord? Think you'd be willing to visit the place again in eighty years?"
"Not with a woman aboard," grunted the astrogator.