"Excuse me," he said, breaking into Gillian's ruminations. "But can we go back to the thing I came here about? I know the problems you're wrestling with are bigger and more important than mine, and I'd help you if I could. But I can't see any way to change your star-G.o.d troubles with my bow and arrows.

"I'm not asking you to risk your ship, and I'm sorry about being a pest. . . . But if there's any way you could just let me . . . well ... try to swim ash.o.r.e, I really do have things I've got to do."

That was when the tytlal rolled back onto his feet, wearing a look of evident surprise on his narrow face. Spines that normally lay hidden in the fur behind his ears now stood in stiff bristles. Moreover, Dwer felt sure he glimpsed something take shape briefly, in the air above Mudfoot. A ghostly wisp, less than vapor, which seemed to speak of its own accord.

So do I, it said, evidently responding to Dwer's statement.

Things to do.

Dwer rubbed his eyes and would gladly have dismissed the brief specter as another imagining ... another product of the pummeling his nervous system had gone through.

Only Gillian must have noted the same event. She blinked a few times, pointed at the now-worried expression on Mudfoot's face . . . and burst out laughing.

Dwer stared at her, then found himself breaking up, as well. Till that moment, he had not yet decided about the beautiful Earthwoman. But anyone who could set Mudfoot back like that must be all right.

Rety AS THE GUARD ESCORTED HER TO THE CAPTIVES' cell, she eyed several air-circulation grates. Schematics showed the system to be equipped with many safety valves, and the ducts were much too small for prisoners to squeeze through.

But not for a little urrish male, armed with borrowed laser cutters.

Rety's plan was chancy, and she hated sending her "husband" into the maze of air pipes. But yee seemed confident that he would not get lost.

"this maze no worse than stinky pa.s.sages under the gra.s.s plain, "he had sniffed while examining a holographic chart, "it easier than dodging through root tunnels where urrish grubs and males must scurry, when we have no sweet wife pouch to lie in." yee curled his long neck in a shrug, "don't you worry, wife! yee take tools to locked-up men. we do this neat!"

That would be the critical phase. Once Kunn and Ja.s.s were beyond the brig airlock, all the other obstacles should quickly fall. Rety felt positive.

Two prison cells had red lights glaring above reinforced hatches. The far one, she knew, contained Jophur rings that had been captured in the swamp. The little g'Kek named Huck was helping the Niss Machine interrogate those captives. Rety had racked her brain to come up with a way they might fit her plan, but finally deemed it best to leave them where they were.

This Streaker ship won't dare chase us, once we get a star boat outside . . . but the Jophur ship might. Especially if those rings had a way to signal their crew mates.

As the guard approached Kunn's cell, Rety fondled a folded sc.r.a.p of paper on which she had laboriously printed instructions, sounding out the words letter by letter, stretching her newborn literacy to the limit. She knew it must look wrong, but no one could afford to be picky these days.

KUN I KAN GIT U OF UV HIR WANT TU GO?.

So went the first line of the note she planned slipping him, while pretending to ask questions. If the Danik pilot understood and agreed to the plan, she would depart and set yee loose to worm his small, lithe body through Streaker's dueling system. Meanwhile Rety had selected good places to set fires-in a ship lounge and a cargo locker-to distract the Streaker crew away from this area while Kunn used smuggled tools to break out. If all went well, they could then dash for the OutLock, steal a star boat, and escape.

There's just one condition, Kunn. You gotta agree that we get away from here. Away from these Farthers, away from Daniks and Rothens and Jophur monsters and all that c.r.a.p. Away from Jijo.

Rety felt sure he'd accept. Anyway, if he orJa.s.s give me any trouble, they'll find they're dealin' with a different Rety now. The guard maneuvered his walker unit carefully in the narrow hallway. The gangly machine had to bend in order for him to bring a key against the door panel. Finally, it slid aside. Rety glimpsed two bunks within, each supporting a blanket-covered 'human form.

"Hey, Kunn," she said, crossing the narrow distance and nudging his shoulder. "Wake up! No more delayin' or foolin' now. These folks want t'know how you followed 'em. . . ."

The blanket slipped off, revealing his shock of glossy hair, but there was no tremor of movement.

They must have him doped, she thought. , hope he's not too far under. This can't wait!

Rety shook harder, rolling Kunn toward her- And jumped back with a gasp of surprise.

The Danik's face was purple. His eyes bulged from their sockets, and his tongue had swollen to fill his mouth. The dolphin guard chattered a dismayed squeal in the instinctive animal language of his kind. Rety struggled with shock. She had grown up with death, but it took all her force of will to quash the horror rising in her gorge.

Somehow, she made herself turn toward the other bunk.

sara "Ob, Doctor Faustus was a good man, He whipped his scholars now and then; When he whipped them he made them dance, Out of Scotland into France, Out of France, and into Spain, Then he whipped them back again!"

Emerson's song resonated through the Hall of Spinning Disks, where dust motes sparkled in narrow shafts of rhythmic light.

Sara winced at the violent lyrics, but the starman clearly enjoyed these outbursts, gushing from unknown recesses of his scarred brain. He laughed, as did a crowd of urrish males who followed him, clambering through the scaffolding of Uriel's fantastic machine, helping him fine-tune each delicate part. The little urs cackled at Emerson's rough humor, and showed their devotion by diving between whirling gla.s.s plates to tighten a strap here, or a pulley there, wherever he gestured with quick hand signs.

Once an engineer, always an engineer, Sara thought. At times, Emerson resembled her own father, who might go I silent for days while tending his beloved paper mill, drawing more satisfaction from the poetry of pulping hammers and rollers than the white sheets that made literacy possible on a barbaric world.

A parallel occurred to her.

Paper suited the Six Races, who needed a memory storage system that was invisible,row s.p.a.ce. But Uriel's machine has similar traits-an a.n.a.log computer that no satellite or s.p.a.ceship can detect, because it uses no electricity and has no digital cognizance. Above all, Galactics would never imagine such an ornate contraption.

And yet it was beautiful in a bizarre way. No wonder she had dreamed shapes and equations when her eyes first glimpsed this marvel through cracks in her delirium. Each i time a disk turned against a neighbor's rim, its own axle' rotated at a speed that varied with the radial point of contact. If that radius shifted as an independent variable, the rotation changed in response, describing a nonlinear function. It was a marvelously simple concept . . . and h.e.l.lishly hard to put into practice without years of patient trial and error, Uriel first saw the idea in an old Earth book-a quintes sentially wolfling concept, briefly used in an old-time Amero-Eurasian war. Soon after, humans discovered digital computers and abandoned the technique. But here on Mount Guenn, the urrish smith had extended it to levels never seen before. Much of her prodigious wealth and pa.s.sion went into making the concept work.

And urrish haste. Their lives are so short, Uriel must have feared she'd never finish before she died. In that case, what would her successor do with all this?

An array of pillars, arches, and boo scaffolding held the turning shafts in proper alignment, forming a threedimensional maze that stretched away from Sara, nearly filling the vast chamber. Long ago, this cavity spilled liquid. magma down the mountain's mighty flanks. Today itj throbbed with a different kind of creative force.

Light rays played a clever role in the dance of mathematics. Glancing off selected disks, pulselike reflections fell onto a stretch of black sand that had been raked smooth across the floor. Each flash affected the grains, causing a slight spray or rustle. Hillocks grew wherever glimmers landed most often.

Uriel even found a use for lightning crabs, Sara marveled.

On Jijo, some sh.o.r.elines were known to froth during electrical storms, as these tiny creatures kicked up sand in frenzied reaction. We thought it might be static charges in the air, making them behave so. But clearly it is light. I must tell Lark about this, someday.

And Sara realized something else.

The crabs may be another Buyur gimmick species. Bioengineered servants, reverted to nature, but keeping their special trait, even after the gene meddlers left.

Whatever their original function, the crabs now served Uriel, whose hooves clattered nervously as the sandscape swirled under a cascade of sparkling light. Individual flashes mattered little. It was the summed array over area and time that added up to solving a complex numerical problem. Near Uriel, the little chimp, Prity, perched on a high stool with her drawing pad. Prity's tongue stuck out as she sketched, copying the sand display. Sara had never seen her little a.s.sistant happier.

Despite all this impressive ingenuity, the actual equations being solved were not profound. Sara had already worked out rough estimates, within a deviance of ten percent, by using a few simple Delancy approximations. But Lester Cambel needed both precision and accuracy under a wide range of boundary conditions, including atmospheric pressure varying with alt.i.tude. For that, machine-derived tables offered advantages.

At least now I understand what it's all for. In her mind, she pictured bustling activity beneath the towering stems of a boo forest, throngs of workers laboring, the flow of acrid liquids, and discussions in the hushed, archaic dialect of science.

They may be crazy-Lester especially. Probably the effort will backfire and make the aliens more vicious than ever. Dedinger would look at this-along with all the semaph.o.r.es, gliders, balloons, and other innovations-and call it the futile thrashing of the d.a.m.ned.

Yet the attempt is glorious. If they pull it off, I'll know I was right about the Six. Our destiny was not foretold by the scrolls, or Dedinger's orthodoxy ... or Lark's, for that matter.

It was unique.

Anyway, if we're to be d.a.m.ned, I'd rather it be for trying.

Just one thing still puzzled her. Sara shook her head and murmured aloud.

"Why me?"

Kurt, the Tarek Town exploser, had acted as if this project desperately needed Sara, for her professional expertise. But Uriel's machine was already nearly functional by the time the party arrived from Xi. Prity and Emerson were helpful at making the a.n.a.log computer work, and so were books Kurt hand-carried from Biblos. But Sara found herself with little to contribute.

"I only wish I knew why Uriel asked for me."

Her answer came from the entrance to the computer vault.

"Is that truly the only thing you wish to understand? But that one is easy, Sara. Uriel did not ask for you at all!"

The speaker was a man of middling stature with a shock of white hair and a stained beard that stood out as if he were constantly thunderstruck. Kawsh leaves smoldered in his pipe, a habit chiefly indulged in by male hoons, since the vapors were too strong for most humans. Politely, Sage Purofsky stood in the draft of the doorway, and turned away from Sara when exhaling.

She bowed to the senior scholar, known among his peers as the best mind in the Commons.

"Master, if Uriel doesn't need my help, why was I urged to come? Kurt made it sound vital."

"Did he? Vital. Well, I suppose it is, Sara. In a different way."

Purofsky's eyes tracked the glitter of rays glancing off spinning disks. His gaze showed appreciation of Uriel's accomplishment. "Math must pay its way with useful things," the sage once said. "Even though mere computation is like bashing down a door because you cannot find the key."

Purofsky had spent his life in search of keys. "It was I who sent for you, my dear," the aged savant explained after a pause. "And now that you're recovered from your ill-advised spill down a mountainside, I think it's high time that I showed you why."

It was still daytime outside, but a starscape spread before Sara. Clever lenses projected gla.s.s photoslides onto a curved wall and ceiling, recreating the night sky in a wondrous planetarium built by Uriel's predecessor so that even poor urrish eyesight might explore constellations in detail. Sage Purofsky wore stars like ornaments on his face and gown, while his shadow cast a man-shaped nebula across the wall.

"I should start by explaining what I've been up to since you left Biblos . . . has it really been more than a year, Sara?"

"Yes, Master."

"Hmm. An eventful year. And yet ..."

He worked his jaw for a moment, then shook his head.

"Like you, I had grown discouraged with my former field of study. At last, I decided to extend the cla.s.sical, precontact geometrodynamic formalisms beyond the state they were in when the Tabernacle left the solar system."

Sara stared.

"But I thought you wanted to reconcile pre-contact Earth physics with Galactic knowledge. To prove that Einstein and Lee had made crude but correct approximations . . . the way Newton preapproximated Einstein."

That in itself would have been a daunting task-some might say hopeless. According to reports brought by the Tabernacle, s.p.a.ce-time relativity was ill regarded by those alien experts hired by the Terragens Council to teach modern science to Earthlings. Galactic instructors disdained as superst.i.tion the homegrown cosmology humans formerly relied on-the basis of crude star probes, crawling along at sublight speeds. Until the Earthship Vesarius fell through an undetected hyperanomaly, ending humanity's long isolation, Einstein's heirs had never found a useful way to go t faster-although some methods had been recorded in the

Galactic Library for over a billion years.

After contact, humans scrimped to buy some thirdhand hyperships, and the old mathemetric models of Hawking, > Purcell, and Lee fell by the wayside. In trying to show validity for pre-contact physics, Purofsky had taken on a strange, perhaps forlorn, task. , "I had some promising results at first, when I restated the !'

Serressimi Exalted Transfer ShUnt in terms compatible with old-fashioned tensor calculus."

"Indeed?" Sara leaned forward in her chair. "But how did you renormalize all the quasi-simultaneous infinities? You'd almost have to a.s.sume-"

But the elder sage raised a hand to cut her off, unwilling to be drawn into details.

"Plenty of time for that later, if you're still interested. For now let's just say that I soon realized the futility of that approach. Earth must by now have specialists who understand the official Galactic models better than I'll ever hope to. They have units of the Great Library, and truly modern ' computer simulators to work with. Suppose I did eventually manage to demonstrate that our Old Physics was a decent, if limited, approximation? It might win something for pride, showing that wolflings had been on the right track, on our own. But nothing new would come of it."

Purofsky shook his head. "No, I decided it was time to

go for broke. I'd plunge ahead with the old s.p.a.ce-time I approach, and see if I could solve a problem relevant to Jijo-the Eight Starships Mystery."

Sara blinked. "You mean seven, don't you? The question of why so many sooner races converged on Jijo within a short time, without getting caught? But isn't that settled?" She pointed at the most brilliant point on the wall. "Izmunuti started flooding nearby s.p.a.ce with carbon chaff twenty centuries ago. Enough to seed the hollow hail and change our weather patterns, more than a light-year away. Once the storm wrecked all the watch robots left in orbit by the Migration Inst.i.tute, sneakships could get in undetected." "Hr-rm . . . yes, but not good enough, Sara. From wall inscriptions found in a few Buyur ruins, we know two transfer points used to serve this system. The other must have collapsed after the Buyur left."

"Well? That's why the Izmunuti gambit works! A single shrouded access route, and the great Inst.i.tutes not scheduled to resurvey the area for another eon. It must be a fairly unique situation."

"Unique. Hrm, and convenient. So convenient, in fact, that I decided to acquire fresh data."

Purofsky turned toward the planetarium display, and a distant expression crossed his shadowed face. After a few duras, Sara realized he must be drifting. That kind of absentmindedness might be a prerogative of genius back in the cloistered halls of Biblos, but it was infuriating when he had her keyed up so! She spoke in a sharp tone.

"Master! You were saying you needed data. Is there really something relevant you can see with Uriel's simple telescope?"

The scholar blinked, then c.o.c.ked his head and smiled. "You know, Sara ... I find it striking that we both spent the last year chasing unconventional notions. You, a sideline into languages and sociology-yes, I followed your work with interest. And me, thinking I could pierce secrets of the past using coa.r.s.e implements made of reforged Buyur sc.r.a.p metal and melted sand.

"Did you know, while taking pictures of Izmunuti, I also happened to snap shots of those starships? The ones causing so much fuss, up north? Caught them entering orbit . . . though my warning didn't reach the High Sages in time." Purofsky shrugged. "But to your question. Yes, I managed to learn a few things, using the apparatus here on Mount Guenn.

"Think again about Jijo's unique conditions, Sara. The collapse of the second transfer point . . . the carbon flaring of Izmunuti . . . the inevitable attractiveness of an isolated, shrouded world to sooner refugees.

"Now ponder this-how could beings with minds as agile as the Buyur fail to notice advance symptoms of these changes, about to commence in nearby s.p.a.ce?"

"But the Buyur departed half a million years ago! There

PART EIGHT.

ILLEGAL RESETTLEMENT OF FALLOW WORLDS has been a predicament in the Five ; Galaxies for as (ar back as records exist. There are many causes ror this recurring problem, but its most enduring basis is the paradox of Reproductive Logic.

-,KC_-!AIIv^ beings from countless diverse worlds tend to share one common trait-sellpropagation. In some species, this maniiests as a conscious desire to have onspring. Among other races, individuals respond to crude instinctive drives ior either s.e.x or xim, and spare little active attention to the consequences.

However different the detailed mechanisms may be, the net enect remains the same. left to their own inclinations, organic liteforms will reproduce their kind in numbers exceeding the replacement rate. (_,ver periods of time that are quite brici by stellar standards, the resulting population increase can iwiitly overburden the carrying capacity or any selt-sustaintng ecosystem. (SEE: AJ TACHED SORTED EXAMPLES.) Species do this because each tecund in may not have been any symptoms back then. Or else they were subtle."

"Perhaps. And that's where my research comes in. Plus your expertise, I hope. For I strongly suspect that s.p.a.cetime anomalies would have been noticeable, even back then."

"s.p.a.ce-time . . ." Sara realized his use of the archaic Earth-physics term was intentional. Now it was her turn to spend several silent duras staring at a blur of stars, sorting implications.

"You're . . . talking about lensing effects, aren't you?"

"Sharp la.s.s," the sage answered approvingly. "And if I can see them-"

"Then the Buyur must have, and foreseen-"

"Like reading an open book! Nor is that all. I asked you here to help confirm another, more ominous suspicion."

Sara felt a frisson, climbing her spine like some insect with a million ice-cold feet.

"What do you mean?"

Sage Purofsky briefly closed his eyes. When he reopened them, his gaze seemed alight with fascination.