Wall Around a Star

FIFTEEN

Down below them, Cuckoo's huge weather engine was building up a great cyclonic storm. The engine ran on heat, as in every other astronomical body, but Cuckoo's heat transport came from the inside to escape into space. Cuckoo's storm had been growing for weeks, and it had its counterpart on the orbiter, a slow, vast vortex that swept beings Jen Babylon had never seen before in toward the center of the structure. That was where the huge com­puter farlink whispered to itself, surrounded by its banks of flat-picture screens and stereostage enclosures for holo­grams. In one stage the great virtual-image globe of Cuckoo itself turned slowly, most of its surface still blank or only vaguely sketched in from satellite reconnaissance; a few sections thick with detail of continents, mountains, seas. But the globe of Cuckoo was not the display the beings swarmed toward. That display came from Doc Chimp's tachyon camera, far below the surface.

The stereostage images were terribly disturbing. They were also terribly poor in quality, for the chimpanzee's hand-held camera caught only quick and fragmentary glimpses. But that was where farlink came in. Its power­ful circuits selected every bit of information, assayed it for validity, weighed it for importance, assigned it a place in a greater picture. It edited, interpreted, selected, so that its algorithms extracted maximum information from the most corrupt signal. The result was displayed in the central stereo­stage, while details were shown flat on any of the half- hundred circling screens. What the horde of beings saw was not a moving hologram but a series of stills—but it was enough. The entire orbiter was in a flap, as the vortex drew every living thing into that single room.

There was no calm in this storm's eye. The great dome was bedlam. Shouts, screeches, roars; rataplan of Scorpian robots, neighing sobs of Canopans. Doc Chimp, tugging fretfully at the long green feather in his cap, dodged a dense cloud of Boaty-Bits and muttered to Jen Babylon, "It's feeding time at the zoo!" His shoe-button eyes were fixed woefully on the image his other self was transmitting from so far away.

Babylon nodded, his face drawn. "Smells worse than any zoo I've been in," he agreed absently, and was rewarded with a burnt-rubber smell of indignation as the T'Worlie that had hovered by his shoulder flounced away. He sighed, wincing as a Scorpian hissed past, drumming at the top of its timpani. His Pmal was overloaded; with every being trying to communicate at once its language matches were completely unable to keep up. What came to his ears was a jumble of words and phrases, and simple static.

For no one understood what was happening. That the expedition was traveling downward into the heart of Cuckoo was obvious; that they were passing through me­tallic tunnels, galleries, chambers was apparent. But what did it mean? Everyone—every being—had a theory. The Scorpians had discovered secret plans of the tunnel, leading to some incredible trove or treasure; the Scorpians denied it with fury. The Sheliaks were in league with the deltaforms to trigger tectonic forces and destroy Cuckoo entirely—the Sheliak nearest that theorizer nearly destroyed him in re­sponse. The Canopans accused the Sirians of having en­slaved their one representative in the expedition with an illegal Purchased People unit; the Sirians screeched that the facts were right, but the enslavement had gone the other way. No species accepted responsibility. Every one vowed that its conspecific was a rogue who had been act­ing oddly for some time. Was there truth in any of it? There was no way to be sure—and no way, really, to dis­cuss any of these things intelligently with the overloaded Pmals faltering in the incessant din.

And meanwhile Doc Chimp's little camera recorded a journey that went down, down, down, toward no one could guess what.

Ben Pertin sailed through the whirlwind of beings to link arms with Babylon and bring himself to a stop. Babylon glanced around warily, then whispered: "Anything new?"

Pertin shook his head angrily. The one secret they had retained was the tachyon cap; in Pertin's own chamber Zara was wearing it, trying to eavesdrop on the Purchased People in the expedition. "You can't pick out the ones you want," he complained, "and then when you do get one it doesn't tell you anything." He moodily watched the slow build-up of images on the stereostage and detail screens for a moment. "What we need," he said, "is a Watcher. They know more than we do!"

Org Rider, hanging close by in the little group of Earth primates, shook his head. "There's none on the orbiter now," he said positively. "And that one"—he frowned at the stereostage—"is insane." And indeed, the image looked very much that way; the hideous being had been captured in midflight, against a background of dull metal tunnel ceiling and walls, its horrid face screwed up in an expres­sion of rage and fear.

Emotions were running high everywhere, Jen Babylon thought. The crowd in the room was seething with anger, resentment, fear—and other, less guessable emotions, which had no clear counterpart in the human repertory. You could not tell what the Boaty-Bits, for instance, were feeling. Angry or overjoyed, they still danced in their dense swarm like flies in the light over a swimming pool on a summer's eve. The T'Worlie alone seemed unmoved. Noth­ing of smaller scope than galactic could touch their ancient feelings. They did not possess either fear or resentment in any personal sense; what they wanted of life was to learn and ponder, and all the revelations of secrets and conspir­acy provided for them was a set of new phenomena to study.

And perhaps the TWorlie were right. Babylon told him­self justly that the "enemy"—the rogue beings leading that expedition—had really done nothing that could not be ex­plained. Indeed, nothing for which an explanation was really required. They were exploring new ground. Well, given the chance, what being among them would not? There was no evidence to convict them of a crime. No crime had been committed. The most you could say against them was that they had acted in secret.

Yet in his heart Babylon knew that something was terri­bly wrong. The individual beings were rogues; the collec­tive purpose of the expedition was threatening.

And he was not alone in that feeling. Each in its own way, the seething mass of beings that hung by the walls, floated in midair, or flapped, clung to stanchions and each other—that raucous, malodorous congeries of nightmare shapes that were his shipmates—they all shared his fear, rage, and indignation. The Canopans had demanded a Grand Council. The T'Worlie had agreed, out of their own patient curiosity more than any desire to prosecute; and beings Babylon had never seen before, or even dreamed of, were still flocking to the great interior farlink chamber.

How they bellowed, and how they stank! The handful of true humans—loosely enough defined, to be sure, to in­clude Org Rider and Doc Chimp—huddled near the en­trance, trying not to be choked by the hot-iron stink of the Scorpian robots and the vinegar scent of the inquisitive T'Worlie, and the fouler reeks of the beings that looked like kittens, or roaches, or sea anemones or copper-wire mantises. There were beings here Babylon had never seen before: the anemone-creature, with its violet shell shading to dark purple, slithering eel-like shapes with tentacled eyes, a soft-bodied sort of beetle with many legs, a human form—but no! It was not human! It was a winged woman's figure, but silvery and with blank, opaque eyes. "It's an edited form," Doc Chimp whispered nervously when Baby­lon asked. "Don't be deceived by the way she looks! She's not human, no, not a bit!" And before Babylon could ask more, she was lost to sight in the crush.

There had to be three hundred beings in the room! Not counting the Boaty-Bits, who were so thrust about and jostied by the crowd that they could not maintain the integrity of their swarm, but buzzed about like a smoked-out bee­hive. Doc Chimp, morose and distraught, flung himself into the mob to get a better look at the hologram, then wriggled his way out again. "Good fellow primates," he said distractedly to Pertin and Babylon, "I can't see a thing! And it's me down there, and I tell them it's my cam­era that's sending them the stereopictures, and they push me out of the way!" Babylon gave no answer, because he could think of none to give. The chimpanzee wrinkled up his long black lips and muttered, "Here's Redlaw, anyway. 1 forgot to tell you I saw him coming."

Pertin spun eagerly around. "Anything?" he demanded. The big man looked around carefully before replying.

"Not the way you mean," he said, loud enough to be audible above the din, too low for his words to carry be­yond the small group. "But there's something, all right. Your girlfriend, Benpertin."

"Doris?" Pertin scowled sourly. "What can there be about her that would be important?" He caught a glimpse of Babyon's expression and added, "Oh, come on, she's just a convenience—I don't care if she lives or dies! Why should I? And don't look at me that way—do you know how she got to be a Purchased Person? Torched the house where her husband and three babies were sleeping! Killed them all! You think I really care about someone—"

Redlaw put his hand on the other man's arm, his expres­sion showing that his feelings were no more kindly than Babvlon's. "It isn't exactly Doris," he said softly. "It's the creature that owns Doris who has something to say. You'd better hear it, all of you."

Doc Chimp muttered, "But the Grand Council, Mr. Redlaw! It's supposed to start any minute—"

Redlaw's deep growl cut him off. "The council doesn't know what this is all about. Come! And bring that T'Wor­lie if you can find him."

As almost the oldest resident of Cuckoo Station, Ben Pertin had certain privileges. One was the room he slept in.

It was a faceted polyhedral chamber, most of the interior faces filled with flat pictures of scenes from his lives. Past the stereostage was an exterior shot of Sun One. Over his bed loomed the immense majesty of Knife-in-the-Sky Mountain. In the center of the room, fitted with soft bind­ing tapes to keep an occupant from floating away in his sleep, was Pertin's bed; and as they entered someone lifted a head from it to gaze at them.

From the side of the room Zara came toward them, the helmet slung from one hand. Her expression was strained. All she said was, "I'm glad you're here."

Ben Pertin—Babylon could not decide whether his voice was surly or embarrassed—scowled at the bed. "Doris giv­ing you any trouble?" he demanded.

"It's not Doris," said Zara, and from the lips of the fig­ure on the bed a woman's voice, unearthly slow and care­fully formed, said:

"Attend the person Zara. This person has already com­municated." And the woman turned her face to the covers of the bed, waiting.

Doc Chimp turned his leathery face to Zara. "And what does that mean?" he asked plaintively.

"She's been telling me things," Zara said. The strain on her face had not eased; the sound of her voice was trou­bled. "She won't tell me much about her home planet. Least of all, where it is. But it's hot. I believe in her real body—that is, its real body, the body of the thing that bought Doris—molten sulfur flows in its veins instead of watery blood. But they have a civilization not too much unlike ours: that is, it's a collection of individuals, not a single multicellular society like the Boaty-Bits. And they differ widely among themselves—like us—not like, say, the T'Worlie or the Sheliaks."

Mimmie, hanging inconspicuously by the doorway, danced gently forward. "Disagreement," he chirped. "TWorlie find other TWorlie quite individual."

"I know," Zara agreed, "but you're more, well, united than human beings, aren't you? Anyway. The important thing is, some of their individuals on this fire planet are doing the same sorts of things humans are on Earth. It's their equivalent of Kooks."

The female human figure on the bed stirred restlessly. It did not lift its head, but the unearthly voice, muffled by the bedclothes, said: "Speak of zero-mass tachyons."

Doc Chimp exploded, "That was private information! Good heavens, Ben! I didn't know Homo sapiens primates could be so naive! Didn't you know better than to discuss that sort of thing with your fancy woman, knowing she was Purchased?"

Pertin said defensively, "I didn't! Tell them, Doris—I mean, you there, whoever you are!" But Zara interrupted.

"Ben is right," she said. "The . . . being wasn't repeat­ing what she had heard from us. She was telling a deep secret of her own race." The figure on the bed moved con­vulsively, but was silent. "They have used zero-mass tach­yons for their own purposes for a long time, but have never shared the knowledge with the rest of the galaxy. And they suspect that their . . . Kooks are controlled with zero- mass tachyons from somewhere else." She took a deep breath. "They think it's from Cuckoo," she finished. "And they think that the members of the expedition are con­trolled in the same way, or at least their leaders are."

The figure lifted its head. "These are instructions," it said tonelessly. "Display spherical object. Consider relation­ships. Advise all other beings." And the woman's figure tossed away the restraining straps, rose from the bed, and moved silently out of the chamber and away.

Babylon saw the strange, almost fearful look on Pertin's face as his gaze followed her, and understood something of what was in Pertin's mind. "Consider relationships," in­deed! Babylon knew what relationships his friend was con­sidering. Doris was a Purchased Person, whose distant owners were only academically interested in human sexual practices. Usually she was permitted to share Pertin's bed only when they had no other plans for her. But sometimes they were in direct control. How strange it must be, Baby­lon thought, to murmur drowsy endearments into a worn- an's ear, and find a reply from her remote and inhuman owners!

But there was not much time for such reflections now. The T'Worlie moved silently to the center of the room, fac­ing its human companions. It chirped, "Concurrence. Rec­ommendation to advise all other beings is agreed." It floated silently for a moment, its five eyes seeming to stare at each of them in turn, then added a quick series of chirp­ing whistles and a pungent smell of clove. The Pmals rapped out the translation: "Observation: Situation becom­ing critical. Proposal: All information now be shared, in­cluding data from helmet, information store obtained from wrecked vessel—and communication just received through being identified as Doris."

Redlaw boomed, "He's right! We don't have a choice— so let's do it!"

If the orbiter had been excited before, now it was like an anthill gone mad. Beings of every fantastic shape flew and hurled themselves along the corridors. The news had sped faster than a tachyon transmission, and each race, almost each individual of every race, reacted with its own special pattern of consternation and anger, and even fear. Hardly a civilized planet in the Galaxy, it now seemed, had been spared its equivalent of the Kooks; and the suggestion that they were all part of some incredible conspiracy was explo­sive. Chugging Scorpian robots sped through swarms of milling Boaty-Bits without warning; Sheliaks and Pur­chased People stopped each other at the intersections with furious bursts of screeches and rattles from the overworked Pmals; and all of them tried to crowd their way into the farlink chamber, where the T'Worlie were feeding data into the computer as fast as it could be accepted.

First Babylon had overseen three great Sheliaks, func­tioning as porters, as they bodily moved the store of hexa­gonal rods and their reader into the chamber. Then they obeyed the Doris-being's command.

The T'Worlie had plugged farlink into the circuits, and every datum from the hexagonal rods was entering its data stores. The images were slower to build, but they were clearer, more detailed—farlink was not only observing, it was pondering what it saw, matching it against a vast store of information. Doc Chimp was given the task of feeding the hexagons into the reader; he fumbled through the stack until he found the key one—the "spherical object"—and slipped it into its slot.

At once the translucent block cleared, and the great metal bubble shone forth inside it. Doc touched the scan­ning plate, and the image began to go through its cycle— slowly now, as farlink studied each new display in turn and enhanced the images. First the featureless metal globe. Then the cutaway sections. Then the schematics: a net­work of scarlet structural members, replaced by an inter­linked system of ivory-colored arteries—transportation pas­sages? Something like that, perhaps. Then, coded in bright silver, a set of mirror-finished rings, making a sort of basketwork duplicate of the sphere itself.

The swarm of beings in the chamber hissed and mut­tered to each other, but no clear voice emerged. Doc Chimp pushed himself back and stared morosely at the im­age. "I don't see anything sensible," he complained. "What's it supposed to mean?"

Zara said doubtfully, "Well, let's see. It's a sphere. An artifact. I suppose it represents some instrument or ma­chine—a spacecraft, maybe?"

Babylon ventured, "I understand there are old orbiting vessels you can't approach around Cuckoo—like the wrecked ship?"

Pertin shook his head. "They don't look a bit like that," he growled, and then called, "farlink? Any interpreta­tions?"

The clear, cold voice of the machine replied, "Negative. Analysis continuing. More data required."

The humans looked at each other, and Zara shrugged. "The helmet?"

Org Rider nodded. "We have no choice," he declared. "Benpertin, please produce the helmet. We must share this information, too!"

* * *

The excitement and resentment that followed the giving up of the helmet—how dare these Earth beings withhold valuable data!—was only exceeded by the uncertainty of how to use it. Obviously the helmet could not be worn by farlink as it could by a human being—or by the beings who had made it; obviously, if those who had worn it sim­ply told farlink what they had seen they would omit much priceless data, or corrupt it. At last a Sheliak plunged into the center of the group and plastered itself against farlink's data-input terminals, extruding a bubble of its flesh toward the helmet. The bubble crept inside; the doughy mass of Sheliak flesh suddenly contorted, and then was still. Pertin nodded grudgingly. "Knew the damn beasts would be good for something one day," he declared. "They can shift their organs and nerves around as easily as their bodies—it's giving direct transmission of its nervous impulses to the computer!"

Babylon shook his head unbelievingly. "Raw sensory in­puts? How can farlink read them?"

"That's farlink's problem, and it'll solve it," Pertin boasted. "Just wait and see!"

It was easy enough advice to follow—there was no real alternative!—but the mob of beings in the chamber was getting louder and more raucous.

The first sign that anything happened was that the great globe from the hexagon-rod data disappeared. The cube re­mained clear, but it contained no information. There was a gasp, buzz, hiss, whistle—whatever sounds each made— from the beings; but as moments passed and the image did not reappear the surprise reverted to angry impatience.

Then, at a single stroke, all the dozens of circling flat- picture screens were wiped blank, while the holo of the expedition on the center stereostage firmed up. It became more clear in all its parts, and began to move in real time. farlink was doing its job. As it matched the images from the other Doc Chimp's camera against the data from the helmets—and against that vast collection of other informa­tion that made its datastore—it filled in the gaps, interpo­lated details, made the scene as real as if the observers were standing at some vantage point and beholding the scene itself.

Since there was nothing else to look at at the moment, every being in the chamber was looking at the scene, and one, at least, felt a queer stirring, half a memory, half a long-forgotten apprehension. Jen Babylon shook his head. What was it? The scene showed the toiling line of porters and leaders passing through the narrow corridors and emerging into a great chamber, kilometers wide and deep, with walls that seemed to be set with bright, winking jewels and a network of cables and branching cyclopean struc­tural beams. All rose from a floor formed of silver-white lines that looked thinner than threads, too fragile and too far apart to hold anything.

"I've seen that before," he muttered, mostly to himself, but beside him Zara caught the words and looked at him curiously.

"You have, Jen? Where?"

He shook his head. "I can't remember," he confessed. "Maybe in a dream. Quite a while ago. —No, it's gone. But somehow that looks familiar—and frightening!"

She studied his face carefully before she said, "Please think hard, Jen. It may be important."

And perhaps it was, but Babylon got no chance to think about it more carefully, nor did any being in the chamber, about that or about anything else. For the blank cube sud­denly sprang into life. It showed the ball of layered silver rings, then the ivory arteries, then the bright scarlet struc­tural members—the same sequence as before, but in re­verse order, as if the artifact was being constructed before their eyes. And much faster, much surer; with a sense of reality and solidity to the images that had been lacking be­fore. Like the first series, the remaining view was the great featureless globe, hanging in space.

But it did not stop there.

The globe clouded over. It showed markings that looked like a satellite's view of a distant planet. First mountains and wide, shallow basins. Then the basins were filled with seas and lakes, and tiny spiderweb lines on the surface filled with liquid to become streams and rivers. The moun­tains sprouted forests; the lowlands were lush with vegeta­tion or bleak with scarred rock and desert sands. At last the atmosphere began to fill with clouds, all sorts of clouds—glowing clouds in a thousand hues in one place, fleecy cumulus and towering cumulonimbus in others, and in one huge patch, covering nearly a tenth of the surface of the globe, a great swirling cyclonic mass.

A great, involuntary sound went up from the crowd star­ing at the display, then a loud, excited buzz. "It's Cuckoo!" cried Org Rider. "That's the big storm that's been develop­ing for weeks now!"

And Ben Pertin laughed queerly. "You're right," he said, half sobbing, "it's Cuckoo. The artifact is Cuckoo. Cuckoo is an artifact. It's not a planet—or a star—or a mere astrophysical anomaly. It's a machine!"

A machine! It was unbelievable—and yet farlink was registering .999-plus certainty, and all around the chamber the flat screens were lighting up, one by one, showing de­tails of the mechanism, cyclopean Cuckoo-girdling bands, great chambers with cryptic contents, vents, and thrust- mountings—it was an engineering plan of some immense edifice, no doubt of that! The hubbub grew to a crescendo, and then there was a silvery chime, farlink wished to speak. Its flat mechanical voice tolled, picked up and translated by a hundred Pmals into a hundred different tongues:

"Analysis complete! Object has been tentatively identi­fied as a Dyson sphere, conjectural astrophysical artifact proposed by Freeman J. Dyson, planet Earth, mid- twentieth century. Dyson suggested that a truly advanced race of technological beings, using ever-increasing amounts of energy, would ultimately devise a scheme to capture the entire energy output of its parent sun by surrounding it with a sphere of matter produced by rearranging the non- stellar components of its solar system—planets, asteroids, comets, satellites, dust and gas clouds, etc.—into a shell, so that no radiant energy could escape the system without being made to do work. Signatures. Dyson proposed that a telescopic search be made for large, light objects radiating faintly in the infrared. No large-scale systematic search was made, and the proposal was forgotten. However, Object Lambda, a.k.a. Cuckoo, possesses these signatures. Details. Reference display one." One of the flat panels was sud­denly surrounded by a halo of flashing color; it displayed the basketwork sphere of layered rings that had already been seen in the records of the wrecked orbiter. "Surface sphere is clearly supported by ring network. Hypothesis: Each ring consists of matter moving at more than orbital velocity, thus generating centrifugal force that keeps the shell from collapsing into the central sun. This high- velocity motion is evidently essentially frictionless. Exact nature of rings and means of their control at present not known. Reference display two." A tiny, incredibly bright spark of light, surrounded by cloudy glow. "This is the central sun, identified as a type F-4, now in an atmosphere of relatively dense plasma extending to the inner surface of the shell. Reference display three." An interior view of the shell, with some sort of tiny objects in slow motion within it. "These are apparent self-reproducing mechanisms, ab­sorbing energy from the star and storing it for purposes not yet established. Reference display four . . ."

But Babylon could look no more. The fourth screen was showing the openings in Cuckoo's poles. High-rimmed holes, each tens of thousands of kilometers across. Nozzles! Thrusters for plasma jets that drove and controlled the in­credible structure . , . but he had absorbed all he could, and he returned to the central marvel.

A Dyson sphere! Now he remembered. It had been in an early astronomy course, before he had settled on his major in linguistics. The instructor had joked about it. Now that communication between scores of alien races was a fact, he said, it was clear that the so-called "Dyson sphere" was simply the ludicrous fantasy of someone who had read too much space fiction as a boy.

Babylon grinned to himself. "If only my old teacher were still alive," he muttered, "this would kill him for sure!"

The T'Worlie that had been hovering unnoticed by his head emitted a cinnamon odor of perplexity. "Query: Ref­erent not understood."

Babylon shook his head. "It doesn't matter." And then, wonderingly, "A Dyson sphere! But—out here, in the mid­dle of nowhere? Where could it have come from?"

The T'Worlie danced silently for a moment, then of­fered: "Statement: Representation of galaxy in temple not our own. Conjecture: Home galaxy of artifact builder?"

Babylon stared at him without replying.

Another galaxy? But the nearest other galaxies—the Magellanic Clouds and the Mafei 1 and 2—they were tens of thousands of light-years away. The nearest really big one, M-31 in Andromeda, two million light-years!

He felt his flesh crawling. Who would create an artifact as immense as Cuckoo and send it hurtling through inter- galactic space on a voyage whose duration could not be less than hundreds of thousands of years?

And why?

TWorlie twittering and a sudden reek of new paint caught him: "Reservation," the T'Worlie chirped. "Hy­pothesis of structure surrounding sun difficult to accept. First demurrer: No known form of matter possesses the characteristics required for construction of hypothetical frictionless rings. Second—"

"No," Babylon interrupted, "but then no known object like Cuckoo exists, either!"

The T'Worlie chirped on, disregarding him: "Second de­murrer: Position of stellar object at center of such hypo­thetical shell would be metastable. Inevitable small random displacements from central position would be accelerated by positive gravitational feedback."

Babylon shook his head rebelliously. "Cuckoo exists!"

"Laws of physics also exist," the T'Worlie twittered, and an odor of overripe muskmelon accentuated the words. "Axiom: Laws of physics apply equally throughout the Universe and may not be denied."

Ben Pertin cut in roughly, "What's the use of this argu­ing? You're just saying that what we can see to be true can't be true!"

"Negative," the T'Worlie responded. "Correct interpreta­tion: To reconcile known physical facts with hypotheses regarding Cuckoo requires two corollaries." The T'Worlie danced thoughtfully for a moment, as if it hesitated to say what it must say. A diffident, wondering scent of lilac em­anated from it and, although no human could read expres­sion in a T'Worlie's tiny eyes, Babylon felt a stab of appre­hension at what was coming next.

"Corollary one," the T'Worlie chirped firmly. "Design and construction of 'Dyson sphere' system required techno­logical and scientific skill at levels not now attained by any galactic race. Corollary two: Sphere was constructed, and at present is still controlled, by existing intelligence."

The TWorlie's chirping, and the rattle of the Pmals, lin­gered in the vast chamber and died away into silence.

And then the noise came. For long minutes the swarm of beings had been quiet, hanging on the farlink data and the T'Worlie's observations; but they could be silent no longer. Buzzes, shrieks, whistles, brays—every being was speaking at once.

An existing intelligence! Something that had somehow survived the journey of endless years!

Babylon shouted into the din: "Do you mean that this object has a mind?"

"Perhaps many minds," the T'Worlie chirped somberly, and added, "It must be so."

Babylon turned away, unseeing. Cuckoo as an artifact was hard enough to believe—but to add to that the belief that somehow a guiding intelligence survived within it . . .

His imagination reeled. Only dimly did he sense that some new sound had been added to the noise. Doc Chimp snaked out a long paw and dragged Babylon to his side. The chimp's sad face had suddenly become more woebe­gone than ever as he stared, with the others, at the forgot­ten scene from the camera of his other self, far below. It had changed. There was no resting on the part of the slave procession now; all of them were up and moving, and the expression on the chimp who grasped his arm was mirrored in the one down below the shell of Cuckoo. "It's the Watcher," Doc Chimp moaned. "He's really gone mad now—and I'm down there with him."

"Pull yourself together, Doc," Ben Pertin snarled over his shoulder. "It's just a copy!"

"It's me," the chimp insisted. "And they're fighting, and—oh! Look at the Canopan!"

By now the entire chamber was watching the new chal­lenge to their sanity. Everyone saw the Canopan suddenly covered with a swarm of Boaty-Bits, the wild scuffling, the insane flight of the Watcher, the terrible destruction of the green-glow weapon.

"They're trying to break it up!" Zara cried, as the green- glowing charge hurtled down toward the grating of slender silver rods that hung beneath the jungle of cables and branching structural beams. Babylon's breath caught. Those wire-thin rods were the rings that supported the sphere. If they were broken, the whole surface here would cave, falling toward the central sun—

Or something worse! If the frictionless motion of the un­known stuff of the rings was really more than orbital, any broken ring would mean faster and more dreadful disaster. No longer frictionless, its unknown stuff would tear into the fabric of Cuckoo at velocities that must be hundreds of kilometers a second. Everything it struck would be ex­ploded into incandescent plasma. Including, probably, other rings in its path. Shuddering with something between awe and terror, he imagined all Cuckoo turning into a super­nova.

How many of the supernovas in far-off galaxies, Ben Pertin wondered, were signals of advanced intelligence and ultimate technology snuffed out by catastrophic accident?

Not breathing, he watched the green-shining missile strike the silver rod. It exploded. The whole screen burned with green fire and went abruptly black. The camera had been overloaded.

"They're trying to kill Cuckoo," he tried to say. "Trying to kill us—"

He had no voice. Around him there was silence, then a muffled stir of breath and motion. He tensed in spite of himself, waiting for the final crash of sound, for the walls to buckle around him and the whole world to dissolve into fire ...

It couldn't happen that fast, of course. Cuckoo was too huge. Even a plasma explosion would take time to swallow it all, more time to reach the orbiter.

The screen lit, dimly at first, then with more brightness and clarity. Babylon could breathe again.

"Nobody," Doc Chimp whispered, "nothing could live in that!"

And it seemed true. They could see the cavern again. Apart from the Watcher there seemed no one, no being, alive within the range of the camera, except for a huge man with skin the color of weathered brass, and the other Doc Chimp—and the chimpanzee was blinded.

Even in the stereostage the sight was fearful. The view­ers shrank away from the flare of green light that turned their faces queerly metallic. Ben Pertin laughed—hysteria, Babylon thought; but Doc Chimp took it personally.

"How can you?" he chattered furiously. "I thought you were my friend! If it was you down there—"

"If it was me," Pertin said brutally, "it would come to the same thing. So you're being killed! But we've both been killed so often already it just doesn't seem important any­more. It's the Boaty-Bits! They've been up to something all along. They have a lot of explaining to do—"

His voice broke off. His eyes darted around the room, and his face assumed an expression of comical surprise.

"What's the matter, Ben?" Babylon asked.

"The Boaty-Bits. Don't you see? There's not one of them in this chamber—they've sneaked away!"

At least the noise level had dropped! It was not that the beings on the orbiter were calmer—quite the reverse—but now they were dispersed, as Scorpians and T'Worlie, hu­mans and deltaforms, every being of every race joined in the orbiter-wide hunt. Where were the Boaty-Bits?

Within a few moments Babylon had lost track of the other human beings—Pertin in one direction, Zara in an­other, Org Rider and Redlaw heading for the landers on the assumption that the collective creatures were trying an escape. He and Doc Chimp were flying down a corridor on the trail of a mixed mob of Purchased People and Sheliaks. It taxed all of Babylon's strength, but the chimpanzee was crooning to himself as he pulled them along the hoist-ropes with his powerful simian arms. "Died down there," he sobbed, half to himself, "going to die again! Oh, heaven help this poor old monkey in this terrible world—"

Babylon, panting, tried to reassure him: "But that's not true, Doc," he gasped. "You don't have to die again! Everything's changed now, don't you see?"

The chimp reached out with one long, black-furred arm and brought them to a jolting stop. "Changed?" he de­manded, peering into Babylon's face. "You haven't been here very long, have you? Nothing changes! You just go on dying and dying! It's a pity us monkeys don't get manic depressive, because this is a great place for suicidal types— you get so many chances to act it out! I tell you, they're just going to decide to send down another party through the tachyon transfer, and somebody's sure to say let's take old Doc along, and—"

He stopped in midbreath. "Oh, Dr. Babylon!" he whis­pered softly. "The tachyon chamber. Of course! Come on!"

And, of course, he was right. In less than five minutes they were at the entrance to the tachyon-transport room, a long gaggle of beings trailing them in response to Doc Chimp's agitated yells, and at the door the chimpanzee brought them to a sharp stop. "There you are!" he whis­pered triumphantly. "You see?"

And, sure enough, there inside the chamber was a Sirian eye—perhaps the same renegade who had transported him­self up from the catacombs—surrounded by a furious swarm of the steel-blue collective creatures. "What are they doing?" Babylon demanded.

"Can't tell," the chimp whispered, "but it looks as if they're pulling Purchased-People units out of the store. Only they're not here—"

But there was no more time for speculation; the rest of the lynch mob had caught up with them, and all beings together stormed into the chamber.

Jen Babylon had never seen one sentient being murder another before, but he saw it happen now. There was no stopping the furious mob. The Canopan was the first to die, and as he was struck down, bleeding a pumpkin-yellow ichor, the great equine skull crushed by a blow from a Scorpian, two Boaty-Bits flew out of the fleshy ruff that was its mane. They tried to join the rest of their swarm, but the swarm itself was disorganized, dying bit by bit as each one of them was struck by Sheliak tentacle, Sirian electric bolt or fist, hoof, horn, or whatever other striking appendage any being had. They died in the hundreds, si­lently at first. Then they swarmed together for a moment and buzzed fiercely, a screaming drone that the Pmals ren­dered as:

"Fools! You are doomed! Only collective intelligence will survive—and you will be part of it!"

And then they said nothing more. Not enough of them were left to make an articulate entity, and then there were none of them alive at all.

In Jen Babylon's mind there was room for just so many wonders, so long a list of concerns. His senses were satu­rated and his mind full; and yet something new was clam­oring for attention. It took him a long moment to realize what it was.

The T'Worlie lay huddled and broken in a corner. Its wings fluttered feebly, and it exuded a sour, sick reek that grated on Babylon's senses.

"What's the matter?" he demanded, reaching out to the sad little shape. It drew away from his touch, and the odor changed to something like a wet seabeach back on Earth. Babylon looked up to Ben Pertin. "Something's wrong with the T'Worlie," he said.

The creature chirped feebly—more the rustle of a dying cricket than its normal bright sound. The Pmals did not respond at all. "He's in bad shape," Pertin said, his face drawn. "I've seen it before. T'Worlie aren't built for this sort of thing."

Babylon shook his head in puzzlement. "There was a lot of commotion," he said, "but I didn't see him get hurt." He stretched out a hand again, and the little creature shud­dered.

"Correction," it chirped faintly. "Not hurt. Harmed."

Babylon nodded, thinking he had understood. "Well, hadn't we better get it to medical assistance?" he de­manded, staring around the chamber. Most of the nonhu- man beings were gone now, and only Pertin, Babylon, and the T'Worlie were left in the great chamber.

But the T'Worlie fluttered away. "Negative," it stated. "Harm not physical. Healing required not medical."

Pertin put his hand on Babylon's arm. "I told you," he snapped. "They can't handle this sort of violence, intelli­gent beings destroying one another—"

"I didn't care much for it myself!"

"No. Neither did I. But you and I can survive it, Jen, and I'm not sure Mimmie can." Pertin bent to look more closely at the little batlike being, and the T'Worlie spoke:

"Further correction. Can survive. Have been harmed most gravely. Require therapy."

"Therapy?" Pertin gazed up at Babylon and shook his head to show that he did not know any more than Babylon.

"Confirmation: therapy. Specific techniques necessary: healing constructive analysis and synthesis." The T'Worlie raised itself gently on filmy wings, as if it did not dare put too much strain on them. "Statement: Depart now for ther­apy. Will return."

The orbiter had become quieter, though wandering bands of beings still roamed its corridors, and Babylon had actually drifted off to sleep for a few moments when the T'Worlie returned. It seemed much more energetic and strong, and responded to Babylon's queries with confi­dence.

"Have completed therapy," it stated. "Data developed is of value."

"What data?" Babylon demanded, and listened while the T'Worlie explained what it had done.

And that was nothing more or less than to reason out the explanations of many of the mysteries that had perplexed them: The creature had locked itself in with farlink, seeking escape from the pain of seeing life violated on such a catastrophic scale. And it had come away with what it called a healing hypothesis.

"And what is that?" Babylon demanded.

"Hypothesis: Rings are monatomic structures, e.g., sin­gle atoms."

"Single atoms?" Babylon repeated, not comprehending.

"Confirmation. Data examined include reported exami­nations of individual rings and summarized results from all attempted investigations.

"Physical nature of rings has been unknown and per­plexing. Observed sections are extremely thin horizontal rods supporting the entire surface structure of Cuckoo. These rods appear mirror-bright, reflecting all incident ra­diation unchanged. They are frictionless in motion and ab­solutely hard, unaffected in any observable way by applied forces. They are reported to be magnetic and superconduct­ing—power required for the operation of Cuckoo is be­lieved to be transmitted through them. No natural sub­stance possesses such qualities, and the nature of the rings has remained a riddle, even to farlink."

"But you've solved the riddle?"

"Hypothesis: Rings are atoms—"

"Isn't everything?"

"Question irrelevant until you know hypothesis." A sharp ammonia scent reproved him. "Convergent evidence suggests high probability that each ring is a single atom. The nucleus is not a point but a phenomenon—"

But Babylon could not let him finish. "Did you say a single atom? That's ridiculous. Impossible! There must be something wrong with my Pmal."

"Negative. Translation accurate. Term 'single atom' cor­rect."

"But it can't be!"

A whiff of orange-blossom amusement, fading fast as the still weak T'Worlie whispered, "Correction: Possibility exists. Evidence supports probability. Nucleus not a point but may be described as a phenomenon previously un­known. Term proposed for this is 'nuclear polymer.' De­scription: a chain of bound quarks maintaining a positive charge that hold a thick electronic sheath surrounding the chain. Such object would be friction-free and indefinitely strong, thus satisfying requirements observed."

Babylon's mind was spinning. He was no physicist, but he knew enough to be shocked at the notion of an atom of stellar size. "Is that possible, Mimmie?"

"Datum: The rings exist. Alternative hypotheses cannot account for them."

"But—" Babylon shook his head, trying to imagine a single atom stretched into a ring capable of orbiting a star. "But what's it made of?"

"Atomic structure of source material irrelevant to hy­pothesis. Possibly iron, which is a massive and strongly magnetic element, relatively common."

"How—" He blinked. "How could such things be made?"

"Hypothesis presents few clues. The process of creation must have required enormous mass, enormous energies, and the use of technologies ultimately advanced. Probably not explicable in context of known physics."

The T'Worlie fluttered suddenly closer, and he heard shouting and hissing and hooting in the corridor behind him as a last random fragment of the mob straggled across it.

"Forgive me." A whiff of something like ether. "My ethical trauma not yet entirely healed. I require additional intellectual therapy."

It was fluttering away.

"Mimmie, wait!" Babylon hushed his voice. "If you don't realize it, your life's in danger. I think you've really cracked the riddle of Cuckoo. You've got the secret we all came for. A precious secret, if you don't know that—which places you in more than merely mental danger. People— things—will kill you for it, if you aren't very careful."

"You misunderstand the nature of my psychic trauma if you term it merely mental." An ammoniac tang. "You should know that physical danger and physical death have never mattered to my people."

Yet it came back a little toward him.

"If you don't like violence," he muttered, "remember those plotters. Trying to blow up all Cuckoo!"

"If my hypothesis is valid, such plots can be forgotten." Its chirp seemed almost cheerful. "Known evidence indi­cates numerous past attempts to damage or destroy ring structure, which have always failed. Hypothesis suggests they will always fail."

"If the rings are atoms—" He frowned, trying to grasp that novel reality. "Some atoms aren't stable."

"Ring stability abundantly proven." The T'Worlie flitted closer, with a scent like hot asphalt. "Cuckoo is supported by several billion rings that have functioned for many mil­lion years with no evidence of any breakdown."

"Suppose the ring system collided with something?"

"Experiment untried. Hypothesis suggests rings might survive stresses even more extreme. If ring cores do consist of quarks arrayed in linear chain, protected by dense elec­tronic sheath, known physics indicates that it would be lit­erally unbreakable." A breath of oleander. "Superstructures supported by ring system, however, would not survive ex­periment."

"Literally?" He stared. "You mean to say the rings themselves can't be destroyed?"

"Conclusion unwarranted. Hypothesis implies that rings are vulnerable."

"To what?"

"To intelligent application of the same advanced science by which they were created. They are artifacts. Process of creation, however unknown, is irrelevant to hypothesis. In common experience, many processes can be reversed." With a burnt-toast scent of apology, it was gliding away.

"Care, Mimmie," he whispered after it. "Better not trust anybody. Your hypothesis could be true, but it could also get you killed. Maybe all of us."