One day very late in his training, with perhaps half a year-subjective remaining until his graduation as a full-fledged agent of the Stasis, Pierce returned home from a week sampling the plague-pits of fourteenth-century Constantinople. He found Xiri in an unusually excited state, the household all abuzz around her. "It's fantastic!" she exclaimed, hurrying to meet him across the atrium of their summer residence. "Did you know about it? Tell me you knew about it! This This was why you came to our time, wasn't it?" was why you came to our time, wasn't it?"

Pierce, greeting her with a fond smile, lifted young Magnus (who had been attempting to scale his back, with much snarling, presumably to slay the giant) and handed him to his nursemaid. "What's happened?" he asked mildly, trying to give no sign of the frisson he'd momentarily felt (for their youngest son could have no idea of how his father had just spent a week taking tissue samples, carving chunks of mortal flesh from the bubo-stricken bodies of boys of an age to be his playmates in another era). "What's got everyone so excited?"

"It's the probes! They've found something outrageous in Messier 33, six thousand light-years along the third arm!"

Pierce-who could not imagine finding anything outrageous in a galaxy over a million light-years away, even if mapping it was was the holy raison d'etre of this Civilization-decided to humor his wife. "Indeed. And tell me, what precisely is there that brings forth such outrage? As opposed to mere excitement, or curiosity, or perplexity?" the holy raison d'etre of this Civilization-decided to humor his wife. "Indeed. And tell me, what precisely is there that brings forth such outrage? As opposed to mere excitement, or curiosity, or perplexity?"

"Look!" Xiri gestured at the wall, which obligingly displayed a dizzying black void sprinkled with stars. "Let's see. Wall, show me the anomaly I was discussing with the honorable doctor-professor Zun about two hours ago. Set magnification level plus forty, pan left and up five-there! You see it!"

Pierce stared for a while. "Looks like just another rock to me," he said. Racking his brains for the correct form: "an honorable sub-Earth, airless, of the third degree, predominantly siliceous. Yes?"

"Oh!" Xiri, n.o.bly raised, did nothing so undignified as to stamp her foot; nevertheless, Magnus's nursemaid swept up her four-year-old charge and beat a hasty retreat. (Xiri, when excited, could be as dangerously p.r.o.ne to eruption as a Wolf-Rayet star.) "Is that all you can see? Wall, magnification plus ten, repeat step, step, step. There. There. Look at that, my lord, look!" Look at that, my lord, look!"

The airless moon no longer filled the center of the wall; now it stretched across it from side to side, so close that there was barely any visible curvature to its horizon. Pierce squinted. Craters, rills, drab, irregular features and a scattering of straight-edged rectangular crystals. Crystals? Crystals? He chewed on the thought, found it curiously lacking as an explanation for the agitation. Gradually, he began to feel a quiet echo of his wife's excitement. "What are they?" He chewed on the thought, found it curiously lacking as an explanation for the agitation. Gradually, he began to feel a quiet echo of his wife's excitement. "What are they?"

"They're buildings! Or they were, sixty-six million years ago, when the probes were pa.s.sing through. And we didn't put them there ..."

THE LIBRARY AT THE END OF TIME.

A Brief Alternate History of the Solar System: Part Two.

... And then the Stasis happened: SLIDE 7.

After two hundred and fifty million years, the continents of Earth, strobe-lit by the mayfly flicker of empires, will have converged on a single equatorial supercontinent, Pangea Ultima. These will not be good times for humanity; the vast interior deserts are arid and the coastlines subject to vast hurricanes sweeping in from the world-ocean. As the sun brightens, so shall the verdant plains of the Earth; but the Stasis have long-laid plans to deflect the inevitable.

Deep in the asteroid belt, their swarming robot c.o.c.kroaches have dismantled Ceres, used its ma.s.s to build a myriad of solar-sail-powered flyers. Now a river of steerable rocks with the ma.s.s of a dwarf planet loops down through the inner system, converting solar energy into momentum and transferring it to the Earth through millions of repeated flybys.

Already, Earth has migrated outward from the sun. Other adjustments are under way, subtle and far-reaching: the entire solar system is slowly changing shape, creaking and groaning, drifting toward a new and more useful configuration. Soon-in cosmological terms-it will be unrecognizable.

SLIDE 8.

A billion years later, the Earth lies frozen and fallow, its atmosphere packed down to snow and nitrogen vapor in the chilly wilderness beyond Neptune. This This was never part of the natural destiny of the homeworld, but it is only a temporary state-for in another ten million years, the endlessly cycling momentum shuttles will crank Earth closer to the sun. Fifty million years after that, the Reseedings will recommence, from the prokaryotes and algae on up; but in this era, the Stasis want the Earth safely mothballed while their technicians from the Engineering Republics work their magic. was never part of the natural destiny of the homeworld, but it is only a temporary state-for in another ten million years, the endlessly cycling momentum shuttles will crank Earth closer to the sun. Fifty million years after that, the Reseedings will recommence, from the prokaryotes and algae on up; but in this era, the Stasis want the Earth safely mothballed while their technicians from the Engineering Republics work their magic.

For thirty million years the Stasis will devote their timegate to lifting ma.s.s from the heart of a burning star, channeling vast streams of blazing plasma into ma.s.sive, gravitationally bound bunkers, reserves against a chilly future. The sun will gutter and fade to red, raging and flaring in angry outbursts as its internal convection systems collapse. As it shrinks and dims, they will inflict the final murderous insult, and inject an embryonic black hole into the stellar core. Eating ma.s.s faster than it can reradiate it through Hawking radiation, the hole will grow, gutting the stellar core.

By the time the Earth drops back toward the frost line of the solar system, the technicians will have roused the zombie necrosun from its grave. Its accretion disk-fed with ma.s.s steadily siphoned from the brown dwarfs...o...b..ting on the edges of the system-will cast a strange, harsh glare across Earth's melting ice caps.

Replacing the fusion core of the sun with a ma.s.s-crushing singularity is one of the most important tasks facing the Stasis; annihilation is orders of magnitude more efficient than fusion, not to say more controllable, and the ma.s.s they have so carefully husbanded is sufficient to keep the closely orbiting Earth lit and warm not for billions, but for trillions of years to come.

But another, more difficult task remains ...

SLIDE 9.

Four and a quarter billion years after the awakening of consciousness, and the Milky Way and Andromeda galaxies will collide. The view from Earth's crowded continents is magnificent, like a chaos of burning diamond dust strewn across the emptiness void. Shock waves thunder through the gas clouds, creating new stellar nurseries, igniting millions of ma.s.sive, short-lived new stars; for a brief ten-million-year period, the nighttime sky will be lit by a monthly supernova fireworks display. The huge black holes at the heart of each galaxy have shed their robes of dust and gas and blaze naked in ghastly majesty as they streak past each other, ripping cl.u.s.ters of stars asunder and seeding more, in a starburst of cosmic fireworks that will be visible nearly halfway across the universe.

But Earth is safe. Earth is serene. Earth is no longer in the firing line.

The Long Burn is by far the largest program of the Stasis. Science Empires will rise and flourish, decay and gutter into extinction, to provide the numerical feedstock for the Navigators. The delicate task of ejecting a star system from its galaxy without setting the planets and moons adrift in their orbits is monstrously difficult. Planets are not bound to their stars by physical cords, and gravity is weak; innumerable adjustments to the orbits of all the significant planets will be required if they are to be carried along. The ma.s.s flow of Ceres alone will not suffice. Rocky Mercury has already been dismantled to provide the control mechanisms that keep the necrostar's accretion disk burning steadily; it's Venus's turn to supply the swarming light-sail-driven ma.s.s tugs. A brown dwarf ten times the size of Jupiter will fuel the rocket, an entire stellar embryo pumped down to the blazing maw in the course of a million years.

Galactic escape velocity is high, and escape velocity from the local group is even higher. The Long Burn will last ten thousand centuries. Each year that pa.s.ses, the necrostar will be moving a meter per second faster. And when it comes to an end, the drastically redesigned solar system will be racing away from the local group of galaxies at almost a thousandth the speed of light-straight toward the Bootes Void.

SLIDE 10.

Over the next billion years, Starship Earth and its dead star will rendezvous with the other components of their lifeboat fleet; an even hundred brown dwarf stars, ten to fifty times as ma.s.sive as Jupiter and every last one dislodged and sent tumbling from its home galaxy by the robot probes of the Engineering Empires.

Their ma.s.s will be gratefully received. For Earth is going on a voyage of discovery, where no star has gone before, into the heart of darkness.

Continent of Lies.

Nothing in his earlier life had prepared Pierce for what came next. It beggared belief: a series of synthetic aperture radar scans transmitted by a probe millions of years ago in another galaxy had triggered a diplomatic crisis, threatening world war and civilizational autocide.

The Hegemony, despite being a Science Empire, was not the only nation in this age. (True world governments were rare, c.u.mbersome dinosaurs notorious for their absolute top-down corruption and catastrophic-failure modes: the Stasis tended to discourage them.) The Hegemony shared their world with the Autonomous Directorate of Zan, a harshly abstemious land of puritanical library scientists (located on a continent which had once been attached to North America and Africa); sundry secular monarchies, republics, tyrannies, autarchies, and communes (who thought their superpower neighbors mildly insane for wasting so much of their wealth on academic inst.i.tutions, rather than the usual aimless and undirected pursuit of human happiness); and the Kingdom of Blattaria (whose inhabitants obeyed the prehistoric prophet Haldane with fanatical zeal, studying the arthropoda arthropoda in ecstatic devotional raptures). in ecstatic devotional raptures).

The Hegemony was geographically the largest of the great powers, unified by a set of common filing and monitoring protocols; but it was not a monolithic ent.i.ty. The authorities of the western princ.i.p.ality of Stongu (special area of study: the rocky moons of Hot Jupiters in M-33) had reacted to the discovery of Civilization on the moon of a water giant with a spectacular display of sour grapes, accusing the northeastern Zealantians of fabricating data fabricating data in a desperate attempt to justify a hit-and-run raid on the Hegemony's federal tax base. Quite what the academics of Leng were supposed to do with these funds was never specified, nor was it necessary to say any more in order to get the blood boiling in the seminaries and colleges. in a desperate attempt to justify a hit-and-run raid on the Hegemony's federal tax base. Quite what the academics of Leng were supposed to do with these funds was never specified, nor was it necessary to say any more in order to get the blood boiling in the seminaries and colleges. Fabricating data Fabricating data had a deadly ring to it in any Science Empire, much like the words had a deadly ring to it in any Science Empire, much like the words crusade crusade and and jihad jihad in the millennium prior to Pierce's birth. Once the accusation had been raised, it could not be ignored-and this presented the Hegemony with a major internal problem. in the millennium prior to Pierce's birth. Once the accusation had been raised, it could not be ignored-and this presented the Hegemony with a major internal problem.

"Honored soldier of the Guardians of Time, our grat.i.tude would be unbounded were you to choose to intercede for us," said the speaker for the delegation from the Dean's Lodge that called on his household barely two days after the discovery. "We would not normally dream of pet.i.tioning your eminence, but the geopolitical implications are alarming."

And indeed, they were; for the Hegemony supplied information to the Autonomous Directorate, in return for the boundless supplies of energy harvested by the solar collectors that blanketed the Directorate's inland deserts. Allegations of fabricating data fabricating data could damage the value of the Hegemony's currency; indeed, the aggressive and intolerant Zanfolk might consider it grounds for war (and an excuse for yet another of their tiresome attempts to obtain the vineyards and breadbasket islands of the Outer Nesh archipelago). could damage the value of the Hegemony's currency; indeed, the aggressive and intolerant Zanfolk might consider it grounds for war (and an excuse for yet another of their tiresome attempts to obtain the vineyards and breadbasket islands of the Outer Nesh archipelago).

"I will do what I can." Pierce bowed deeply to the delegates, who numbered no less than a round dozen deans and even a vice-chancellor or two: he studiously avoided making eye contact with his father-in-law, who stood at the back. "If you are absolutely sure of the merits of your case, I can consult the Library, then testify publicly, insofar as I am authorized to do so. Would that be acceptable?"

The vice-chancellor of the Old College of Leng-an inst.i.tution with a history of over six thousand years at this point-bowed in return, his face stiff with grat.i.tude. "We are certain of our case, and consequently willing to abide by the word of the Library of the Guardians of Time. Please permit me to express my grat.i.tude once more-"

After half an hour of formalities, the delegation finally departed. Xiri reemerged from her seclusion to direct the servants and robots in setting the receiving room of their mansion aright; the boys also emerged, showing no sign of understanding what had just happened. "Xiri, I need to go to the Final Library," Pierce told her, taking her hands in his and watching for signs of understanding.

"Why, that's wonderful, is it not? My lord? Pierce?" She stared into his eyes. "Why are you worried?"

Pierce swallowed bitter saliva. "The Library is not a place, Xiri, it's a time time. It contains the sum total of all recorded human knowledge, after the end of humanity. I'm near to graduation, I'm allowed to go there to use it, but it's not, it's not safe safe. Sometimes people who go to the Library disappear and don't come back. And sometimes they come back changed. It's not just a pa.s.sive archive."

Xiri nodded, but looked skeptical. "But what kind of danger can it pose, given the question you're going to put to it? You're just asking for confirmation that we've been honoring our sources. That's not like asking for the place and time of your own death, is it?"

"I hope you're right, but I don't know for sure." Pierce paused. "That's the problem." He raised her hands to his lips and kissed the backs of her fingers. If it must be done, best do it fast. If it must be done, best do it fast. "I'll go and find out. I'll be back soon ..." "I'll go and find out. I'll be back soon ..."

He stepped back a pace and activated his phone. "Agent-trainee Pierce, requesting a Library slot." "Agent-trainee Pierce, requesting a Library slot."

There was a brief pause while the relays stored his message, awaited a transmission slot, then fired them through the timegate to Control. Then he felt the telltale buzzing in the vicinity of his left kidney that warned of an incoming wormhole. It opened around him, spinning out and engulfing him in scant milliseconds, almost too fast to see: then he was no longer standing in the hall of his own mansion but on a dark plain of artificial limestone, facing a doorway set into the edge of a vast geodesic dome made from some translucent material: the Final Library.

A Brief Alternate History of the Solar System: Part Three SLIDE 11.

One hundred billion years will pa.s.s.

Earth orbits a mere twenty million kilometers from its necrosun in this epoch, and the fires of the accretion disk are banked. Continents jostle and shudder, rising and falling, as the lights strobe around their edges (and occasionally in low equatorial orbit, whenever the Stasis permits a high-energy civilization to arise).

By the end of the first billion years of the voyage, the night skies are dark and starless. The naked eye can still-barely, if it knows where to look-see the Chaos galaxy formed by the collision of M-31 and the Milky Way; but it is a graveyard, its rocky planets mostly supernova-sterilized iceb.a.l.l.s ripped from their parent stars by one close encounter too many. Unicellular life (once common in the Milky Way, at least) has taken a knock; multicellular life (much rarer) has received a mortal body blow. Only the Stasis's lifeboat remains.

Luna still floats in Terrestrial orbit-it is a useful tool to stir Earth's liquid core. p.r.o.ne to a rocky sclerosis, the Earth's heart is a major problem for the Stasis. They can't let it harden, lest the subduction cycle and the deep carbon cycle on which the biosphere depends grind to a halt. But there are ways to stir it up again. They can afford to wait half a billion years for the Earth to cool, then reseed the reborn planet with archaea and algae. After the first fraught experiment in reterraforming, the Stasis find it sufficient to reboot the mantle and outer core once every ten billion years or so.

The universe changes around them, slowly but surely.

At the end of a hundred billion years, uranium no longer exists in useful quant.i.ties in the Earth's crust. Even uranium 238 decays eventually, and twenty one half-lives is more than enough to render it an exotic memory, like the bright and early dawn of the universe. Other isotopes will follow suit, leaving only the most stable behind.

(The Stasis have sufficient for their needs, and might even manufacture more-were it necessary-using the necrostar's ergosphere as a forge. But the Stasis don't particularly want their clients to possess the raw materials for nuclear weapons. Better by far to leave those tools by the wayside.) The sky is dark. The epoch of star formation has drawn to a close in the galaxies the Earth has left. No bright new stellar nurseries glitter in the void. All the bright, fast-burning suns have exploded and faded. All the smaller main-sequence stars have bloated into dyspeptic ruddy giants, then exhausted their fuel and collapsed. Nothing bright remains save a scattering of dim red and white dwarf stars.

Smaller bodies-planets, moons, and comets-are slowly abandoning their galaxies, shed from stars as their orbits become chaotic, then ejecting at high speed from the galaxy itself in the wake of near encounters with neighboring stars. Like gas molecules in the upper atmosphere of a planet warmed by a star, the lightest leave first. But the process is inexorable. The average number of planets per star is falling slowly.

(About those gas molecules: the Stasis have, after some deliberation, taken remedial action. Water vapor is split by ultraviolet light in the upper atmosphere, and the Earth can ill afford to lose its hydrogen. A soletta now orbits between Earth and the necrosun, filtering out the short-wavelength radiation, and when they periodically remelt the planet to churn the magma, they are at pains to season their new-made h.e.l.l with a thousand cometary hydrogen carriers. But eventually more extreme measures will be necessary.) The sky is quiet and deathly cold. The universe is expanding, and the wavelength of the cosmic microwave background radiation has stretched. The temperature of s.p.a.ce itself is now only thousandths of a degree above absolute zero. The ripples in the background are no longer detectable, and the distant quasars have reddened into invisibility. Galactic cl.u.s.ters that were once at the far edge of detection are now beyond the cosmic event horizon, and though Earth has only traveled two hundred million light-years from the Local Group, the gulf behind it is nearly a billion light-years wide. This is no longer a suitable epoch for Science Empires, for the dynamic universe they were called upon to study is slipping out of sight.

SLIDE 12.

A trillion years will pa.s.s.

The universe beyond the necrosun's reach is black. Far behind it, the final stars of the Local Group have burned out. White dwarfs have cooled to the temperature of liquid water; red dwarfs have guttered into chilly darkness. Occasionally stellar remnants collide, then the void is illuminated by flashes of lightning, t.i.tanic blasts of radiation as the supernovae and gamma-ray bursters flare.

But the explosions are becoming rare. Now it isn't just planets that are migrating away from the chilly corpses of the galaxies. Stellar remnants are ejected into the void as the galaxies themselves fall apart with age.

s.p.a.ce is empty and cold, barely above absolute zero. The necrostar's course has pa.s.sed through what was once the Bootes Void, but there is no end to the emptiness in sight: there are voids in all directions now. The Stasis and their clients have abandoned the practice of astronomy. They maintain a simple radar watch in the direction of travel, sending out a gigawatt ping every year against the tiny risk of a rogue asteroid, but they haven't encountered an extrasolar body larger than a grain of sand for billions of years.

As for the necrosun's planetary attendants ...

One day they will burn Jupiter to keep themselves warm. And Saturn, and icy Neptune, water bunker for the oceans of Earth. These days have not yet come, for they are still working through the t.i.tans, through Rhea and Ocea.n.u.s, Crius and Hyperion-the brown dwarfs built with Sol's stolen ma.s.s, and the other dwarfs stolen from the Milky Way during the Long Burn. Each brown dwarf burns for many times the age of the universe at the birth of humanity; black holes are nothing if not efficient. But one day they will be used up, the last t.i.tan reduced to a dwarfish cinder; and it will be time to start eating the planets.

Not long thereafter, it will be time for the final Reseeding.

Spin Control.

Pierce stood uncertainly before the door in the dome. It glowed blue-green with an inner light, and when he looked around, his shadow stretched into the night behind him.

"Don't wait outside for too long," someone said waspishly. "The air isn't safe." "The air isn't safe."

The air? Pierce wondered as he entered the doorway. The gla.s.sy slabs of an airlock slid aside and closed behind him, thrice in rapid succession. He found himself in a s.p.a.cious vivarium, illuminated by a myriad of daylight-bright lamps shining from the vertices of the dome wall's triangular segments. There were plants everywhere, green and damp-smelling cycads and ferns and crawling, climbing vines. Insect life hidden in the undergrowth creaked and rattled loudly. Pierce wondered as he entered the doorway. The gla.s.sy slabs of an airlock slid aside and closed behind him, thrice in rapid succession. He found himself in a s.p.a.cious vivarium, illuminated by a myriad of daylight-bright lamps shining from the vertices of the dome wall's triangular segments. There were plants everywhere, green and damp-smelling cycads and ferns and crawling, climbing vines. Insect life hidden in the undergrowth creaked and rattled loudly.

Then he noticed the Librarian, who stood in the clearing before the doors, as unnaturally still as a plastinated corpse.

"I haven't been here before," Pierce admitted as he approached the robed figure. "I've used outlying branches, but never the central Library itself."

"I know." The Librarian pushed back the hood of his robe to reveal a plump, bald head, jowly behind its neat goatee, and gimlet eyes that seemed to drill straight through him.

Pierce stopped, uncertain. "Do I know you?"

"Almost certainly not. Call me Torque. Or Librarian." Torque pointed to a path through the vegetation. "Come, walk with me. I'll show you to your reading room, and you can get started. You might want to bookmark this location in case you need to return."

Pierce nodded. "Is there anybody else here?"

"Not at present." Torque sniffed. "You and I are the only living human beings on the planet right now, although there may be more than one of you present. You have the exclusive use of the Library's resources this decade, within reason."

"Within reason?"

"Sometimes our supervisors-yours or mine-take an interest. They are not required to notify me of their presence." There was a fork in the path, around a large outcropping of some sort of rock crystal, like quartz; Torque turned left. "Ah, here we are. This is your reading room, Student-Agent Pierce."

A white-walled roofless cubicle sat in the middle of a clearing, through which ran a small brook, its banks overgrown with moss and ferns. The walls were only shoulder high, a formality and a signifier of privacy; they surrounded a plain wooden desk and a chair. "This is everything?" Pierce asked, startled.

"Not entirely. Look up." Torque gestured at the dome above them. "In here we maintain a human-compatible biosphere to reprocess your air and waste. We provide light, and heat, although the latter is less important than it will be in a few million years hereabouts. We've turned down the sun to conserve ma.s.s, but it's still radiating brightly in the infrared; the real problems will start when we work through the last bunker reserve in about eighteen million years. The dome should keep the Library accessible to readers for about thirty million years after that, well into Fimbulwinter."

Fimbulwinter: the winter at the end of the world, after the last fuel for the necrosun's accretion disk had been consumed, leaving Earth adrift in orbit around a cold black hole, billions of light-years from anything else. Pierce shivered slightly at the thought of it. "What's the problem with the outside air?"

"We were losing hydrogen too fast, and without hydrogen, there's no water, and without water, we can't maintain a biosphere, and without a biosphere the planet rapidly becomes less habitable-no free oxygen, for one thing. So about thirty billion years ago we deuterated the biosphere as a conservation measure. Of course, that necessitated major adjustments to the enzyme systems of all the life-forms from bacteria on up, and you-and I-are not equipped to run on heavy water; the stuff 's toxic to us." Torque pointed at the stream. "You can drink from that, if you like, or order refreshments by phone. But don't drink outside the dome. Don't breathe too much, if you can help it."

Pierce looked around. "So this is basically just a reading room, like a Branch Library. Where's the real real Library? Where are the archives?" Library? Where are the archives?"

"You're standing on them." Torque's expression was one of restrained impatience: Weren't you paying attention in cla.s.s the day they covered this? Weren't you paying attention in cla.s.s the day they covered this? "The plateau this reading room is built on-in fact, the entire upper crust-is riddled with storage cells of memory diamond, beneath a thin crust of sedimentary rock laid down to protect it. We switched the continental-drift cycle off for good about five billion years ago, after the last core cooling cycle. That's when we began acc.u.mulating the Library deposits. "The plateau this reading room is built on-in fact, the entire upper crust-is riddled with storage cells of memory diamond, beneath a thin crust of sedimentary rock laid down to protect it. We switched the continental-drift cycle off for good about five billion years ago, after the last core cooling cycle. That's when we began acc.u.mulating the Library deposits.

"Oh." Pierce looked around. "Well, I suppose I'd better get started. Do you mind?"

"Not at all." Torque turned his back on Pierce and walked away. "I'll be around if you call me," "I'll be around if you call me," he sent. he sent.

Pierce sat down in front of the empty desk and laid his hands palm down on the blotter. A A continent continent of memory diamond? of memory diamond? The mere idea of that much data beggared the imagination. "It'll be in here somewhere," he muttered, and smiled. The mere idea of that much data beggared the imagination. "It'll be in here somewhere," he muttered, and smiled.

Unhistory.

One of the first things that any agent of the Stasis learns is patience. It's not as if they are short of time; their long lives extend beyond the easy reach of memory, and should they avoid death through violence or accident or suicide, they can pursue projects that would exceed the life expectancy of ordinary mortals. And that is how they live in the absence of the princ.i.p.al aspect of their employment, the ability to request access to the timegate.

Pierce thought at first that the vice-chancellor's request would be trivial, a matter of taking a few hours or days to dig down into the stacks and review the historical record. He'd return triumphant, a few minutes upstream of his departure, and present his findings before the council. Xiri would be appropriately adoring, and would doubtless write a series of sonnets about his Library visit (for poetics were in fashion as the densest rational format for sociological-academic case studies in Leng): and his adoptive home time would be spared the rigor and pity of a needless doctrinal war. That was his plan.

It came unglued roughly a week after his arrival, at the point when he stopped flailing around in increasing panic and went for a long walk around the paths of the biome, brooding darkly, trying to quantify the task.

Memory diamond is an astonishingly dense and durable data substrate. It's a lattice of carbon nuclei, like any other diamond save that it is synthetic, and the position of atoms in the lattice represents data. By convention, an atom of carbon 12 represents a zero, and an atom of carbon 13 represents a one; and twelve-point-five grams of memory diamond-one molar weight, a little under half an old-style ounce-stores 6 1023 bits of data-or 10 23 bytes, with compression.

The continent the reading room is situated on is fifteen kilometers thick and covers an area of just under forty million square kilometers, comparable to North and South America combined in the epoch of Pierce's birth. Half of it is memory diamond. There's well over 1018tons of the stuff, roughly 10 23 molar weights. One molar weight of memory diamond is sufficient to hold all the data ever created and stored by the human species prior to Pierce's birth, in what was known at the time as the twenty-first century. of the stuff, roughly 10 23 molar weights. One molar weight of memory diamond is sufficient to hold all the data ever created and stored by the human species prior to Pierce's birth, in what was known at the time as the twenty-first century.

The civilizations over which the Stasis held sway for a trillion years stored a lot lot more data. And when they collapsed, the Stasis looted their Alexandrian archives, binged on stolen data and vomited it back up at the far end of time. more data. And when they collapsed, the Stasis looted their Alexandrian archives, binged on stolen data and vomited it back up at the far end of time.

Pierce's problem was this: more than 90 percent of the Library consisted of lies.

He'd started out, naturally enough, with two pieces of information: the waypoint in his phone that identified the exact location of the porch of his home in Leng, and the designation of the planetary system in M-33 that had aroused such controversy. It was true, as Xiri had said, that the Hegemony was reveling in the feed from the robot exploration fleet that had swept through the Triangulum galaxy tens of millions of years ago. And he knew-he was certain!-that Xiri, and the Hegemony, and the city of Leng with its Mediterranean airs and absurdly scholastic customs existed. He had held her as his wife and lover for nearly two decades-subjective, dwelt there and followed their ways as an honored n.o.ble guest for more than ten of those years: he could smell the hot, damp summer evening breeze in his nostrils, the scent of the climbing blue rose vines on the trellis behind his house- The first time he gave the Library his home address and the ident.i.ties to search for, it took him to a set of war grave records in the Autonomous Directorate, two years before his first interview with Xiri. He was unamused to note the names of his father- and mother-in-law inscribed in the list of terrorist wreckers and resisters who had been liquidated by the Truth Police in the wake of the liberation of Leng by Directorate forces.

He tried again: this time he was relieved to home in on his return from the field trip to Constantinople-seen through the omnipresent eyes of Xiri's own cams-but was perplexed by her lack of excitement. He backtracked, his search widening out until he discovered to his surprise that according to the Library, the Hegemony was not, in fact, investigating the Triangulum galaxy at all, but focusing on Maffei 1, seven million light-years farther out.

That night he ordered up two bottles of a pa.s.sable Syrah and drank himself into a solitary stupor for the first time in some years. It was a childish and shortsighted act, but the repeated failures were eating away at his patience. The day after, wiser but somewhat irritable, he tried again, entering his home coordinates into the desk and asking for a view of his hall.

There was no hall, and indeed no Leng, and no Hegemony either; but the angry spear-wielding racc.o.o.ns had discovered woad.

Pierce stood up, shaking with frustration, and walked out of the reader's cubicle. He stood for a while on the damp green edge of the brook, staring at the play of light across the running water. It wasn't enough. He shed his scholar's robe heedlessly, turned to face the dirt trail that had led him to this dead end, and began to run. Arriving at the entrance airlock, he didn't stop: his legs pounded on, taking him out of the dome and then around it in a long loop, feet thumping on the bony limestone pavement, each plate like the scale of a monstrous fossilized lizard beneath his feet. He kept the glowing dome to his left as he circled it, once, then twice. By the end of the run he was flagging, his chest beginning to burn, the hot, heavy la.s.situde building in his legs as the sweat dripped down his face.

He slowed to a walk as the airlock came into view again. When he was ready to speak, he activated his phone. "Torque. Your f.u.c.king Library is lying to me. Why is that?" "Torque. Your f.u.c.king Library is lying to me. Why is that?"

"Ah, you've just noticed." Torque sounded amused. "Come inside and we'll discuss it." "Come inside and we'll discuss it."

I don't want to discuss it; I want it to work, Pierce fumed to himself as he trudged back to the airlock. Overhead, three planets twinkled redly across the blind vault of the nighttime sky. Pierce fumed to himself as he trudged back to the airlock. Overhead, three planets twinkled redly across the blind vault of the nighttime sky.