The Singers of Time

2

To Sork Quintero, the teachings of the old human scientists weren't heretical. They were human, and it was Sork's firm plan to learn everything the human race had ever known . . . as well as, God willing, everything the Turtles knew as well. That made Sork's life even harder than it would otherwise have been. Among other things, the effort cost him a lot of sleep. He didn't have time for much of it, when he put in his hours studying the borrowed old tapes after his day's work for the Turtles was through. It cost him pain, too, because it made his head hurt, especially when he tried to understand what those wild old tapes were talking about. Space. Time. The universe. It didn't mean that these were difficult subjects —as long as he didn't try to understand what the old scientists were saying exactly—but what in the world could they mean by something they called "imaginary time"?

When he did try to digest those indigestibles, then his head hurt. Then nothing they said made sense. Then everything the old Earth scientists said was far more alien than the Turtles themselves.

Sork had begun to convince himself that he would never understand the tapes without help. But where was that help going to come from? Certainly not from the Turtles, who would be horrified even to be asked about such things. Not from his twin brother, Kiri, either, because what did Kiri know of such matters?

He wished his twin was awake to talk to, anyway, but when Sork looked into Kiri Quintero's room, he saw that his brother was still bubbling soft snores in his bunk, untroubled by such questions. That was a pity. Kiri might not study these arcane, antique subjects, but Kiri had the power of comprehension. Kiri understood things. Kiri seemed to grasp conceptual matters almost intuitively; his mind functioned in large images—pictures—interactions—relevances. But Kiri was not, when you came right down to it, much help in his twin brother's desperate effort to learn, because Kiri Quintero was very bad at explaining the things he understood to anyone else.

Sork sighed and walked out into the waking-up noises of the Turtle compound, rubbing the back of his head, where the memmie slot sometimes itched. Already the long flatcar trains were rolling in with their cargoes of raw materials for the Turtles. Looking up, Sork could still see stars overhead—and one bright object that was not a star. It slid silently down the heavens as he watched, as bright as Sirius—and, Sork Quintero thought morosely, just as unreachable. But that wasn't fair either, because he recognized the thing. It was human-built! It was the abandoned shell of an old human space station, empty for centuries now, but still an every-night reminder that, once, human beings had ventured into space on their own.

Once. No longer.

A gentle mooing from behind made him move aside to make way for a Taur servant, ready to begin his day's work of cleaning in the Turtle compound. "Good morning," Sork said politely, though he knew it was unlikely the immature Taur would understand.

Then he began wandering aimlessly across the compound, trying to sort out the things he had heard. His head still hurt. And no wonder! Such strange talk! Time . . . real time, imaginary time, time as a dimension just like up and down and sidewise—what could such things mean?

He didn't know. You could not talk about such things with a Turtle, and no human being seemed interested. If he had any sense, he reflected, he would forget about these old lecture chips and concentrate on his real life here in the compound, working for the Turtles. Certainly the Turtles would prefer it if he stopped.

And that was the main reason Sork Quintero was so doggedly insistent on going on.

He rubbed the memo disk scar at the back of his skull reflectively. Listening to the old lecture chips wasn't like using the memo disks the Turtles supplied their most trusted employees. In some ways, listening to the old human-made chips was better. You had a different kind of headache when it was over. Most of all, you could actually remember what was on the chip after you finished playing it. At least, you could if you were lucky. If you played it over often enough. If you could figure out what all the strange old words meant.

As to understanding all the strange things they said, on the other hand—

He shook his head ruefully. Understanding the meaning of all this talk of "cosmologies" (whatever they were) and "universes" (as though there could be more than one!)—that was another matter entirely. He wondered if he would ever comprehend just what the old human scientists were trying to explain—or if he could ever be sure that they did mean something, instead of just being some silly pre-Turtle superstition, as the Turtles insisted—when they would discuss the subject at all.

Sork scratched his chin rebelliously. These centuries-old human scientists were not slaves to superstition! They had built a great civilization, with no help from Turtles or anyone else. His own grandfather's grandfather had seen it!—had lived in that exclusively human world of high technology and freedom, without Turtles, without Taurs, just men and women living and working together in peace and democracy. . . .

Sork stopped himself there out of fairness, for, as the woman he loved was in the habit of pointing out to him, that wholly human world had not been all that peaceful, or even all that democratic.

Reminded of her existence, Sork glanced at his watch. Sue-ling Quong should be coming off duty now, and with his twin brother, Kiri, still abed he could have her all to himself for the hour or so before his own shift started.

Sork thought briefly of breakfast, then gave up the idea and headed across the compound toward the hospital. Working under the memo disk for the Turtles was stressful enough; coupled with the fact that his head ached already, it would be better to tackle it on an empty stomach.

What Sork did for the Turtles was a form of bookkeeping. His job was to handle complex questions of loading the linear induction cars that swarmed up the space ladder. His choices determined the routing of cargoes to one of the three skyhook landing areas—not the nearest, necessarily, but the one with the most current available capacity.

At least, Sork thought that was what he did. He could never really remember what he did under the memo disk. He knew that he was tracking some "values" for the Turtles, but what those values were exactly he could not say.

Yet, the Turtles seemed easy enough to understand—if you took what they said of themselves at face value. Their philosophy was mercantile. They didn't believe in conquest, only in trade. They did, of course, write the rules their trading went by.

Trade they certainly did. Overhead the great space ladder, the Turdes' stairway to the stars, sloped off toward the south and invisibility. As always, there were a dozen cars sliding up and down its cables. Sork looked up at it with his jaw set. Some day, he promised himself, some day he would be in one of those cars, heading out into space the way humans used to do before the Turtles came along. . . .

"Watch it, stupid!" a hoarse human voice shouted.

Sork brought himself up short on the edge of the railroad tracks. A long train of flatcars was coming into the Turtle compound. A uniformed guard, not a memmie—not even a memmie, Sork thought—was scowling at him. "Don't slow the train down!" he barked.

Sork didn't answer. He stood there, more or less patiently, while the train clanked and rattled slowly past. Each car held a rusted, evil-looking chunk of metal. Sork thought he knew what they were: tanks and cannon, old, almost forgotten instruments of war. The kind of thing the Turtles had made unnecessary for humans to have ever again.

It wasn't unusual to see such ancient artifacts come in for shipment up the ladder to orbit. It only meant that somewhere on the Earth the Turtles had ferreted out another old armory and politely, insistently, had made a deal to buy its contents for shipment to wherever they forged such things to their own purposes.

Really, the whole compound was a junkyard. Turtles didn't care about appearances. If, here and there, you could see a few patches of greenery you could be sure that they were nothing to do with the Turtles. Such little plantings were invariably tended by humans in their spare time. The only use Turtles seemed to have for growing vegetation was to eat it, but that they did only rarely. The Turtles didn't need to do much farming for food, because the Turtles ate almost anything, organic or not.

As the last car went by, Sork saw a Turtle waiting on the far side, demonstrating impatience by munching at something —it sounded like rock being crushed. Sork recognized the alien from the rusty carapace and yellow eyes—and mostly from the creature's stunted size. It was the one he worked for.

"Hello, Facilitator," Sork said. That was of course the creature's title, not his name—certainly not his unpronounceable Turtle name. Among themselves the humans had given their own names to the aliens—"Litlun" for this one, because he was smaller than the rest.

The Turtle engaged his transposer and spoke. "Which Quintero are you?" he demanded.

"I'm Sork Quintero," he said. "Your records keeper." He tried to move away to avoid Litlun's tart, musky smell. It had an acid hint of lemon rind and a sharp turpentine tang: it was the smell of Turtles.

The Turtle made a sound of annoyance. He turned without a word and stalked away, his carapace rusty brown in the sunlight. Sork knew that the Turtle was confused by the fact that Sork was an identical twin. It irritated him, and seemed to make him dislike both of them. But that was all right with Sork Quintero, because he didn't like Litlun either.

Oddly, the other Turtles didn't seem to, either. But who could understand what Turtles felt?

Sork stopped at the door of the office of the woman he loved, frowning. An unfamiliar male voice was coming from within. When Sork peered inside he saw a stranger hovering over Sue-ling's desk. The man had a neatly pointed, curly brown beard on a pink, undepilated face. He looked young, but there was a weary sadness in his brown eyes as he waited for Sue-ling to check something out in her records.

Sue-ling gave Sork a quick smile as he entered and the stranger turned to greet him, hand outstretched. "Hello," he said. "I'm Francis Krake."

"Sork Quintero," Sork said, shaking the hand. It was a strong, hard hand, and the man seemed decent enough. But strangers were unusual in the Turtle compound. "What are you doing here?" Sork asked blundy.

"I'm asking the doctor here for a favor," the man said. "It's about my crew. We had a little accident, and they're in the surgery topside—up in the orbital station. So while I'm waiting for them to be ready to fly again I thought I'd take a few days to look Earth over, and I've been asking the doctor to keep checking on them for me."

"A few days isn't much time to see a whole planet," Sork pointed out.

Krake nodded doubtfully, as though unsure he were getting the point. "Actually I've seen Earth before," he said. "It's just that it has been a long time."

Sork didn't doubt that. Even the man's clothes seemed queerly old-fashioned, like something Sork's grandfather might have worn. He asked the man a logical question. "Why didn't you bring your friends down here for treatment?"

Krake looked either embarrassed or resentful, Sork could not tell which. "It's not the first time they've been hurt," he said stiffly. "They were picked up by the Turtles at the same time I was, but they were in a lot worse shape—almost dead, in fact." He thought for a moment, then corrected himself. "I guess you'd have to say they were really dead, until the Turtles took care of them. You see, they'd crashed in the Andes. Their limbs were broken, they were suffering from frostbite. The Turtles fixed them up, gave them a lot of prostheses—"

He stopped there. After a moment, he added, "Anyway, the way things arc with them now, they do better with Turtle medicine than human."

"Sue-ling's a very good doctor!"

"I'm sure she is! I didn't mean to hurt her feelings." The man looked over at her sadly. "I'm just not very good with girls any more," he confessed. "With people at all, I guess."

Sue-ling looked up from the message on her communicator. "Well," she said, "they say your people are doing fine, Captain Krake. And IVe asked the orbit crew to keep me informed if there's any change."

Krake nodded. "That's good. I'll call in from time to time, if you don't mind." He hesitated, then confided, "I thought I'd check out my old home. It'll be changed in a lot of ways, but still I'd like to visit it. And is it all right if I leave some of my gear with you until I get back?"

"Of course. Call in whenever you like, and I'll tell you what I hear from the orbit station. And I hope you have a good trip, Captain Krake," Sue-ling said, smiling up at him.

"Thank you." Krake stood up to go, then stopped, staring at the back of Sork Quintero's head. He seemed embarrassed again, but in a different way. "Excuse me," he said, his eyes on Sork's skull, "but you're a memmie, aren't you?"

"Of course I'm a memmie," Sork said, surprised. His hand went up to touch the rubbery lips of the implant socket at the back of his skull. "So's Sue-ling. We almost all are here. Naturally. We can't do any real work for the Turtles without a memo disk implant, how else could we handle their technology? It would be impossible."

The stranger shook his head. "Not impossible," he said, and touched his own, unmarked skull. "Thanks for helping me, Doctor," he said to Sue-ling, and turned away.

When Krake had gone Sue-ling gazed absently after him, biting her lip. Sork felt a quick twinge. The last thing he needed was another interesting man to show up in Sue-ling's life. He asked jealously, "Who was that fellow?"

She shook her head. "He's a space pilot, Sork. Can you imagine that? He flies Turtle ships."

"Human beings don't fly Turtle ships!" Sork objected. "He isn't even a memmie!"

"I know, but that's what he says. He has his own interstellar wave-drive ship. The Turtles gave it to him. It has small chemical rocket ships attached—scout ships—so he can land where there isn't any ladder, can you imagine that?"

"Why would they let him do that?"

"For their convenience, of course, what else? He goes to the kinds of planets the Turtles don't like—you know, the warm, wet kind, with oceans. Like the Earth, really."

"And you believe all that?" Sork asked indignantly.

The woman he loved gave him an affectionately understanding look. She was a beautiful woman—eyes almond-shaped but intensely blue, skin fair, hair gleaming coppery red —and the look she gave him was fondly tolerant. "Why would he lie to me? He's really interesting, Sork, and I do hope his shipmates are all right." Then, remembering, "And do you know what else he says? He told me he is the oldest human being in the universe."

He stared at her, not comprehending. "He doesn't look any older than I am," he objected, but Sue-ling was shaking her head.

"He's been in space," she explained. "On a wave-drive ship, traveling at almost the speed of light."

"Oh," said Sork, comprehending at last. The Turtle interstellar wave-drive spacecraft moved at a velocity so close to c that the time of their decades-long travel was shrunk to a matter of a few days for those aboard. "It's time dilation! Just as it says on those tapes!"

"That's right." She nodded, then gave him an inquiring look. "Did you come here because you wanted something?" she asked.

"To see you, of course," he said promptly.

She smiled at him, sweetly enough. "Of course. Still, I thought maybe you had another reason—like running out of the astronomy lectures?" And when he confessed that he had, she reached down into her desk for a fresh supply.

Sork gazed fondly at the back of her bent head, where a neat circle of her lustrous, coppery hair had been depilated for her memo disk implant socket. It might have looked ugly to most human beings. Not to Sork Quintero. There was a socket in his own skull, but that wasn't the point; the point was that since the first moment he had seen Sue-ling Quong, just arriving at the Turtle compound when the university she had worked at had closed down, nothing about her had seemed ugly to Sork Quintero.

Sork turned the little box of chip recordings over in his hands wistfully. "I wish I understood what they're talking about in these lectures," he sighed. "Do you think I could ask one of the Turtles to help me make out this quantum mechanical stuff?"

She looked at him with shock. "Are you insane? Have you forgotten what happened last time?"

"Of course not," he said resentfully. "Litlun threw a fit. Said it was a sign of my essential instability to listen to those blasphemous 'songs,' and threatened to report me if I kept on. Why do you suppose they call them 'songs'? And why blasphemous?"

"What difference does that make? Do you want to be thrown out of the reservation?"

"No, but—"

"But that's exactly what would happen. You know that! The Turtles hate that sort of talk! I'm pretty sure that was one of the reasons why they closed my school down, because some of the physics professors were still teaching what they called quantum mechanics. That's blasphemy from their point of view—there's nothing about quantum mechanics in the divine revelations of the First Mother! That kind of heresy upsets them, Sork. I think they'd destroy these tapes if they could think of a legitimate way of getting their hands on them."

"Don't let them do that, Sue-ling!"

"Well, of course I won't," she promised. "But you have to be careful! You know what would happen if you offended their religion. You'd be out of here in a minute! You couldn't be a memmie any more—"

"What's wrong with that?"

She paused, biting her lip. This man was so infuriating sometimes! Then, controlling herself, "Be reasonable. What else can you do? Do you think there are any high-tech jobs for humans outside the Turtle compounds? You'd make a rotten farmer, Sork." She shook her head maternally. "No, stay here, keep your mouth shut, don't get tossed out of civilization just because of silly curiosity."

He gave her a challenging look. "If I did get thrown out, would you miss me?"

"Of course I would," she said, summoning up all the patience she had.

"A lot?" he persisted.

"Just as much as I would miss Kiri," she promised.

He left it at that. It was not the answer he wanted, but it was the answer she always gave. Sork Quintero loved his brother, Kiri, in spite of the fact that they were so different. But there were times when he could have wished Kiri Quintero a few oceans away. And those times had started when Sue-ling Quong appeared on the scene.

She was watching him. "Oh, Sork," she sighed, "I'm sorry. I know I'm making trouble between you and Kiri."

"There wouldn't be any trouble if you'd just pick one of us and quit going to bed with the other," he told her brutally.

For a moment her anger almost burst forth. What possessive, self-centered pigs men were! The fact was that she loved both of the twins—and, naturally, did what was right and natural to do when you loved someone. But why did each of them feel he had to own her?

Then her sense of humor won out. She grinned. "Could be worse. Look at the bright side, Sork, dear. There's only two of you, and there are plenty of other human women—so count your blessings!" He was looking at her steadily. "I mean," she said, beginning to wonder if Sork's sense of humor was responding to her own, "how would you like it if you were Turtles, a whole race of males and only the one female Mother in all the universe?"

Sork gave the woman he loved a hostile stare. "It doesn't help to joke," he said.

"I'm only saying—"

"I know what you're saying, Sue-ling." He shook his head, suddenly wistful. "I wish you and I could go off somewhere by ourselves, just the two of us."

"Where would we go?" she asked sensibly.

"Anywhere! Anywhere but here, doing anything but working for the Turtles. This life just isn't good enough."

Sue-ling Quong studied him, trying to find some way of soothing his bad mood. "But Sork, dear," she said tentatively, "we're all better off this way. Think of everything the Turtles have done for us." She gestured out the window at the trains of scrap metal. "Look at all those rotten old war machines! I think it's fine that the Turtles take them off our hands for scrap. We don't need them any more, because we don't have any more wars. The Turtles have seen to that! And no more terrorists, no more crime, no more addictive drugs—it's a good bargain we made with them, Sork!"

Sork glared at her. "Faust," he snapped. And when she looked puzzled, "Didn't you ever hear of Faust? There was stuff about him on one of the old lecture tapes, before I got into the science ones. This Faust was supposed to have made that kind of bargain with the Devil, and it cost him his soul. No, Sue-ling, it isn't good enough. It never has been good enough."

Then he paused. Sue-ling, knowing this man so well, knew what was coming next. She could almost feel the sensation of Sork shifting gears in his mind, as he switched from one mode of thought to another. "Sue-ling," he said, his voice deeper and huskier, "have I ever told you that your eyes have sunshine in them? They make the whole day dawn for me."

She sighed, not because she wasn't pleased. "Oh, Sork," she said, "go on and get to work. You'll be late. And I'm about ready to sack in."

She put her face up to be kissed and watched him leave her office, pensive. Sork and Kiri, Kiri and Sork! They were so different.

There was no doubt in Sue-ling's mind that she loved them both dearly. She did her best to love them equally, too, though that was harder. It was Sork who usually made it so— aggressive Sork, always demanding what he wanted, which was generally more time in bed with her. Kiri was less demanding.

Kiri was not, however, less loved. She was certain of that. She was certain, too, that the twins loved each other, but it did sometimes occur to her that Kiri Quintero loved his brother a tiny bit more than he really needed to. When Sork demanded, Kiri nearly always gave way.

Yet each touched her heart. Even in the way they spoke to her. Kiri Quintero's most romantic speech to her was "You're beautiful," or, "I love you." Never anything more; and yet if he told her she was beautiful in those same words a thousand times, somehow each time was new. There would be a different look in his eye or quirk of his lips. If Kiri had few words, he made each one do for a thousand shades of meaning. And Sork—

Oh, Sork! Every day he made a new speech. The problem was that she never knew just what kind of speech it would be. There were times when Sork Quintero spoke to her in tones that were so curt as to barely miss being humiliating, the times when he was caught up in some design of his own and lost sight of everything else. Yet other times he could be a poet. He praised her eyes—and Sue-ling knew that, really, she had quite ordinary eyes—but according to Sork Quintero they were stars, they were deep wells of clear spring water, they were sparks of burning flame. Of course, they weren't any of those things. They were just eyes. And her skin was only skin (Peach blossom! Golden silk! Such nonsense!), as her lips were only lips and the rest of her body no more and no less than any reasonably healthy young female of her genetic background should have. It was all wordplay with Sork. Worse, some of it, she was nearly sure, was lifted almost bodily from the old lecture chips on romantic poetry that he had read so assiduously before moving on to other subjects. . . .

Still, it was endearing wordplay. It was meant to please her and, because Sork meant that so intently, it did.

Whereas Kiri—

Hell, she said to herself, getting up from her desk, stop this. There's no point.

Sue-ling Quong knew that sooner or later she would have to give up one of the twins if she wanted to keep either. She didn't dodge that responsibility in her mind, because Sue-ling was a responsible person.

But she knew that she was not the solution to their problems.

Certainly she was not to Sork's. He wanted something that she couldn't give him, perhaps something that the whole world couldn't give him. For Sork to be happy something had to change—radically change, with unimaginable consequences —and Sue-ling Quong could see no chance, anywhere, that that sort of immense change was in sight.

In this, as it happened, she was very wrong.

The great event that was going to change everything for Sork Quintero (and for everyone else in the universe) had already happened.

In fact it had occurred long before Sork began listening to his old lecture chips—even before he and his twin brother had been born, nearly thirty years earlier. The event itself had actually happened longer ago than that, more than seventy-three years ago, in fact. But as the place where it happened was a bit more than seventy-three light-years away in space, and, as the news could not reach them any faster than the speed of light, neither Sue-ling nor Sork nor anyone else on Earth—Turtle, Taur or human—knew about it yet.

But, all too soon, they would.

When Sork Quintero went to work he had to leave the human quarters and venture into those colder, meaner, underground sections the Turtles reserved for themselves.

He knew the route well. He could have walked it in his sleep, and sometimes he very nearly did, when he had been awake for hours puzzling over the old lecture chips. But still he gazed distastefully around as he crossed the busy streets of the compound. He was aware of the vast cables of the space ladder, which stretched up and out of sight into the clouds to the south and east of the reservation. There was no hope of seeing the top of the ladder, of course, though sometimes, on a clear night, the eye could follow a cable for a long, long way just after dusk or just before dawn, while its upper reaches were still lighted by the sun which had already set for those on the surface.

Sork Quintero knew when he had left the human areas. The difference was sharp. Now there were symbols of the First Mother all over, the great winged female Turtle figure that represented the—perhaps—goddess of the entire Turtle race. Or so people said. Sork wondered if it were really true 'that there was a real Mother of all the Turtles somewhere in space. That was another thing that some people claimed, but was it true? Certainly no human had ever seen a female Turtle.

But no one knew for sure. The Turtles did not care to discuss their religion—or whatever it was—with unenlightened human beings.

There were fewer humans in this part of the compound. There were a handful of Taurs, the adult-male castrated kind, all wearing memo chips of their own, none of them paying any attention to Sork Quintero as they went about the business the chips ordained for them. Taurs, of course, were common everywhere on Earth now—great meat animals, almost human in body, bull-like as the Minotaur in the head.

Turtles, however, were not common at all, anywhere but here.

Most Earthmen would have been startled by what Sork was seeing. Most Earthmen seldom saw a living Turtle, and only a few humans were ever permitted the privilege of serving the Turtles in one of their compounds. Most humans would have been dazzled by the noise, the lights, the eerie strangeness of that part of the compound. To Sork Quintero it was an old story. He had spent his entire life in one part of the compound or another, without ever going outside.

That was the price you paid. Human beings who accepted memmie service with the Turtles also accepted the Turtles' rules. When you worked in the great northern ground terminal for their space ladder on the ruins of old Kansas City or any other Turtle compound, you stayed on Turtle territory all the time. The only exceptions were when you were sent somewhere on a Turtle errand, and then you usually were chip-driven and knew little of where you went. The compound was where the Turtles provided food, clothing and housing for their full-time memo disk employees. That was a significant fringe benefit that went with the job—

It was also, Sork thought bitterly, the same fringe benefit that was given to the inmates in any prison. Although working for the Turtles paid well, it was even worse than being in one of those old-time armies. It was not a human life at all.

While outside—

Sork shook his head. He didn't want to be outside, either. He wanted to be free.

That thought would have startled most of the humans outside the Turtle compound if they had heard him say it. They felt free enough. After all, the Turtles did not interfere with human activities in any physical way. They hadn't outlawed war, for instance. They had simply traded Turtle technology for military hardware until every nation on Earth was overflowing with Turtle aircraft, Turtle ground vehicles, Turtle appliances and Turtle machines—and had nothing left to conduct a decent war with. The Turtles hadn't abolished nations. They had simply insisted on making their trading contracts with smaller political units, and over a generation or two the superpowers had simply dissolved away. Every human being on Earth knew that the Age of the Turtles was a time of unparalleled peace and plenty for most of the human race. Now human beings lived longer and more prosperously than ever. Humans were generally unmolested by the Turtles—not many humans ever even saw one—as long as they didn't interfere with trade.

It was different, though, with those particular human beings who had become memmies.

When you signed up to work in the Turtle treaty compounds as a memo disk employee, your life changed. By human standards, it wasn't even a comfortable life. The Turtles lived cold. The frigid air of their underground parts of the compound were edged with their acrid muskiness. Their odor was as penetrating as menthol, as eye-tearing as ammonia and, when you got too much of it, as foul as an exhumed grave.

But the memmies had something the free people in the outside world never had. They had access to Turtle technology. Almost all of it.

For all the good it did them, Sork Quintero thought savagely. You could operate any Turtle machine, perform every Turtle task, however complex . . . but, once the memo disk was out, you couldn't any longer remember how.

Sork knew where his direct superior, Lidun, would be waiting for him. His brother, Kiri, would be in the same place, because the brothers had arranged to work the same shifts so that neither would have an advantage over the other with Sue-Ling Quong. But when Sork arrived at the Turtle "refectory" Kiri was not there yet, and Lidun himself was in a part of the place where neither Sork nor any other human could go.

The Turtle was "at meal."

That was to say, Litlun was taking that part of his daily nourishment which did not involve actual eating. To be sure, Turtles did eat in more or less the same way as humans, now and then. Sometimes they even ate organic food, like Taur steaks, or the tart, heavy globes of redfruit—or simply a clutch of grass or weed or a tree limb that came to hand. More often what they ate was inorganic materials. It seemed that almost any kind of matter could form part of a Turtle's diet, since they did not depend on what they chewed and digested to supply them with energy, only with raw materials to replace the cells of their bodies as they wore out. The Turtles' life-giving energy came from a different source entirely. It came directly from radiation.

For that reason, what Litlun and half a dozen other Turtles were doing was basking. They were lying belly up in a sealed room, with a crystal panel through which Sork could look, but which he dared not pass. He was well aware that the radiation inside that room would kill him. Even the Turtles lay there with their eyes covered by the nictitating membranes that prevented blindness.

The Turtles, however, were soaking the radiation up. It was presumably what they had evolved to live on, ages past, on that mysterious home planet no human being had ever seen. But even through the shielding crystal, the light from the globes on the ceiling of that chamber felt as though it were scorching Sork's eyes.

"We'll have to wait, I guess," said a familiar voice, and Sork turned to see his brother, Kiri.

Genetically Sork and Kiri were identical, but few people would have believed that in looking at them. They were the same height, almost to a centimeter; they had the same jet hair, straight as string and almost as coarse; their eyes were the same piercing black. But they were antiparticles of each other. Kiri was an electron, Sork a positron; they were identical in every respect, save in sign. Where Sork was slow and thoughtful Kiri was always in motion; Kiri was the athlete and the impatient one. "You were trying to make time with Sue-ling, weren't you?" Kiri added, feinting a punch at his brother's shoulder—but grinning as he did it.

Sork dodged automatically. He was sensitive to everything that concerned Sue-ling Quong, most sensitive of all when it came from his brother. The trouble was that in their contest for her undivided love, Kiri had the advantage of seniority. It was he who had first met Sue-ling, at her old school called Harvard, while running an errand for the Turtles. He not only met her, but fell in love with her. When her school was abandoned, it was Kiri who persuaded her to come to work in the Turtle compound.

And then all the complications followed when Sork, too, fell in love with her, and Sue-ling found herself loving both at once.

It made for confusion. Not for the first time, Sork wondered if the Turtles had made a mistake in accepting them for memmie duty. Both of them had volunteered, of course, as soon as they were old enough, but the unusual configuration of their brains had bothered the memmie surgeons. He remembered lying there on the operating table, his entire head numb from the jaw up, his eyes frozen on a point in the operating-room ceiling but his ears missing nothing, while the surgeons debated whether the abnormal configurations of their brains disqualified them for the memo disk implant.

In the long run, the surgeons had decided to go ahead with implant sockets for both of the Quintero twins. But sometimes Sork wished they had not.

He turned his mind away from the familiar track. "I just wanted to get some more study tapes from her," he said, without total truth.

Kiri shook his head in mock reproval. He didn't have to say that he thought it was a waste of time. His expression, his whole body stance, said it for him. What he did say was only, "Memo disks."

"Oh, I know," Sork said wearily, "you think we don't need to learn things any more. Just slip in a disk, and then—and then we're somebody else. like us."

Kiri's face showed compassion. "Well," he said, trying to sympathize with his brother's drives, "what now? Some new theory of how the universe began?"

Sork complained, "It's all so confusing! They keep talking about people IVe never heard of and things I can't even imagine, Kiri! Other universes! Black holes, white holes, worm-holes—none of it makes any sense to me. Maybe it doesn't make any sense at all," he conceded unhappily. "The Turtles say they don't believe it. Because the First Mother didn't say it. They call it just human superstition—you know, like alchemy, and phlogiston, and the—what did they call it?—the 'luminiferous ether.'"

Kiri shook his head again, seriously this time. "Not the same," he said briefly.

"Well, I know that. This fellow Hawking must've been pretty bright, from everything they say about him, and so was this other fellow Planck. See, Planck said that at certain levels —very small distances, very high temperatures, all sorts of unusual conditions—the regular laws of physics just didn't apply any more. And then others came along and they said that even time wasn't something that could never be changed. Sometimes cause and effect didn't mean anything, because 'effects' could happen before their 'causes' and—"

Kiri's expression clouded. He was looking over Sork's shoulder, into the Turtles' sunning chamber. "Careful," he whispered. "Did you forget they can hear us, inside there?"

The reminder came too late.

Inside the chamber the Turtles were squawking among themselves, some of them rising, stirring, gazing out indig-nandy at the human brothers.

The largest of the Turtles, the one whose title was Legate-on-Earth, rose and stalked toward the door, followed by Lidun. "You memmies!" Legate-on-Earth barked through his transposes "One dislikes such foolish human talk! One wonders if you wish to continue in memmie service!"

"Sorry," Sork muttered rebelliously. "I was just talking with my brother—"

"Do not talk of evil things!" the Turtle hissed, and stalked away.

Lidun remained, drawn up to his full height beside the open door to the basking chamber. Sork retreated, not anxious to expose himself even to the splash of radiation that would come through the opened doorway. He waited for the explosion that would come from his boss for talking "heresy" in the presence of the other Turtles.

Strangely, it was muted. Litlun said only, "Why do you waste your time with such songs?"

"They're not really songs," Sork said.

The Turtle glared at him. It was hard to read Turtle expressions at best; Turtle faces were stiff-tissued, darkly rigid, their armored eyes set wide apart and moving independently in a way that still disconcerted Sork.

"They are songs," Litlun insisted, "and wicked ones. They are a Taur disease! A hallucination that affects mature males, rendering them unfit for useful labor and dangerous to their handlers! They are not proper for you—especially because of the circumstances of yourself and your egg mate, which leave you vulnerable to disturbances."

"My egg mate? Do you mean Kiri?" Sork challenged the Turtle: "Are you saying that there is something special about us?"

The Turtle hissed thoughtfully to itself, glaring at him. There was no doubt, Sork thought, that Litlun did know something, almost certainly knew as much as the twins themselves did about the circumstances of their birth.

But if so he was not willing to discuss it. "Forget these songs," he ordered. "Leave them to the Taurs. Now come with me to draw your chips. It is time to begin your work." And then he turned and waddled away, fluffing the radiation-absorbing webs attached to his limbs in satisfaction, like any human patting his belly after a feast.

In the "office" of the Turtle, Sork went to work under his memo disk.

The disk fit easily into the slot in the back of his skull. Memo disks were gold and plastic, and not really disks; the objects were almost egg-shaped in plan section. As with everything the Turtles did, there was a practical reason for that: the shape made sure that there was only one way that the disks would fit into the receptor that had been surgically implanted in his skull.

Sork Quintero was at work instantly, as soon as the memo disk slipped into its slot. The memories and data it recorded were now more a part of him than his own recollections; all the thoughts and worries that had troubled him away from the disk were wiped away.

The work that Sork did for the Turtles was a little bit like bookkeeping, keeping track of all the Turtle exports. It was an important job. Sork's work was quite essential to the mercantile Turtles.

In a sense, this job was a promotion. As a memmie, Sork Quintero's work had been sometimes fascinating, usually exhausting, sometimes physically repulsive. In his nine years in Turtle service Sork had done almost every kind of job, from piloting Turtle aircraft to working in the slaughterhouse detail, slicing up Taur carcasses for the kitchens of the compound. It didn't matter what assignment was given to him. Under the disk, Sork was an expert at them all. Any memmie was, because with the appropriate memo disk in place in his skull, he could do any job the Turtles didn't care to do themselves. Which was almost every job they considered boring, or physically stressful for them in the hot, damp planet of Earth.

So what made Sork a particularly promotable memmie wasn't his skill. The Turtles supplied the skills. What they prized most in a memmie was dependability. So many humans were lazy, or drank when they were off duty, or got involved in personal affairs and came late or sick to work. Not Sork Quintero—

Well, Sork would have had to admit to himself out of fairness, not often Sork Quintero. It was true that there had been a time when he had done a good deal more drinking than his brother liked—or that the Turtles ever found out about. But that had stopped when Sue-ling came into his life, because Sue-ling didn't like it either. And it was a fact that Sork was always on time and never complained about his assignments—at least, not out loud where the Turtles might hear. His Turtle masters liked those traits in their servants. That was why they had "promoted" him (of course, it wasn't the kind of promotion that brought him any more money, and certainly not any more power) to helping to keep their accounts, because that was an area very important to the Tur-des.

They didn't want any problems there. It never occurred to the Turtles to suspect that Sork Quintero did not want to be a memmie any more.

When the day's shift was through, Sork and Kiri left the Turtle work area. Without discussing it, they did what both knew they had been going to do: They headed for Sue-ling Quong's rooms in the hospital area.

Sue-ling had known they were coming, too; so by the time they arrived she was awake, showered, dressed, ready to spend time with the two men she loved. Hand in hand with both of them, she led the way to the hospital refectory. It was breakfast for her, perhaps supper for the two men, but all three had the same thing—Taur steaks, with fried potatoes and huge glasses of fruit juice and, when they were through, cups of hot black coffee.

As the Taur servant filled their cups it mooed politely. Sue-ling said, "Yes, thank you, it was very good."

Kiri chuckled, but it was Sork who put the thought into words. "How do you know what the thing was saying?" he demanded.

"She isn't a thing," Sue-ling said defensively. "Taurs are really quite intelligent, and of course she was saying she hoped we enjoyed our meal."

"Doesn't that strike you as strange?" Sork pursued. "I mean, what is it she hoped we enjoyed eating? Taur!"

Sue-ling shrugged, annoyed. "The fact that they're meat animals doesn't mean we have to treat them like, well, brutes! Kseen has been working here in the refectory for two years, and she is really quite sweet. Just watch her—oh, heaven! What do you suppose is the matter with her?"

For the female Taur had suddenly gone down on her knees, mooing in misery. She had dropped the tray of dishes, and when she turned to look at the three humans, the broad bovine face was racked in misery.

"She's sick," Sork declared.

But his brother was shaking his head. "No," he whispered, listening.

And Sue-ling heard it too. There was another sound, barely heard—a wordless keening from far away. It climbed in volume and pitch, and it was dire.

Sue-ling blinked at the brothers, suddenly afraid. "Is that the Turtles who are making that awful noise?" she whispered.

Kiri nodded somberly. Sork said, his voice taut, "If we can hear this much, this far away, they must be screaming up a storm." He didn't have to say that most of the vocal range of Turtle sounds was well outside the frequencies audible to humans.

"I've never heard anything like it," Sue-ling said.

Sork, whose entire life had been spent in the Turtle compound, nodded slowly. "Nor I. Not even when they worship their goddess. This is something brand-new."

"It must be something really terrible to get them so upset," Sue-ling said, gazing at the Taur, now drunkenly picking herself up and staggering out of the room.

And Sork, his eyes suddenly gleaming with a savage light: "You bet it must—and, oh, God, I hope so!"

Where do the aiodoi sing? If one must ask that one may never know, for the aiodoi are not in a "where." Still, their songs are heard everywhere, except in a few places where those who dwell there have never learned to listen, while the aiodoi themselves hear everything, always, even the faint old songs from distant Earth.

"If you remember when we talked about Hawking's idea of what we called 'the eternal anaconda of time,' you probably also remember that we mentioned that the universe was born out of'vacuum fluctuations.' What we didn't do was tell you what was in the vacuum to fluctuate, or how it fluxed.

"There's a good reason for that. The reason is that we don't know the answer.

"Still, we do know quite a lot about vacuum fluctuations in general, and that's what we're going to take up today. To begin with, there's no such thing as 'empty space.' There isn't

any such thing as a law of conservation of matter and energy any more, either, except perhaps statistically, over time. The ironclad bookkeeping limitations were repealed by Werner Heisenberg, as a logical consequence of his uncertainty principle.

"According to the uncertainty principle, the conservation of energy doesn't have to be exact at every moment. 'Borrowing' is allowed. At some point temporary particles can be created out of nothing at all. However, they have to be 'paid back' later on by disappearing. The new law allows that they can last for a period, which is written as delta-T, in an amount, delta-E, such that delta-T times delta-E is roughly equal to Planck's constant, which you all of course remember is written as h.

"We don't usually see these particles appearing and disappearing before our eyes. There are several reasons for that: they are tiny; they don't last very long; and we don't usually look in the right place. It would be possible for us to see them, I think, or at least to see very clear proof that they exist, if we had some stable superheavy elements to look at. The heaviest natural element we have is uranium, with ninety-two protons. Even the artificially created elements, the ones that are called 'transuranic,' aren't very much heavier. If we had some really massive elements—say, with atomic numbers of two hundred protons or more—the particles we're looking for could be counted on to appear inside those atoms, and they would have definite, measurable effects on the atoms so we could detect them. As it is, they appear only randomly—but they do it everywhere, and all the time.

"Space, all space, is literally filled with these particles, winking in and out of existence. And that is why space is not truly empty.

"That's another reason why a good many physicists refuse to use the term 'empty space' any more. They even go back to the old idea of the 'luminiferous ether'—well, not really to that; but at least to the notion that there is some sort of universal frame, or what we call a rigging vector field, which pervades all of space. You remember, I hope, that some of those scientists, particularly the old Jagiellonian group, in Krakow, Poland, have ventured to use the. word 'neoether' to describe just what the invisible something is that fills the universe.

"I suppose you are now beginning to think that next week we'll be reviving phlogiston and the Philosopher's Stone. No. We don't go that far. But all the same, we have to admit the notion that there is something that exists everywhere."

But the aiodoi simply sang on, for that song, like all other songs, they had been hearing forever.