Raft.

Xeelee Sequence.

by Stephen Baxter.

To my wife, Sandra

Acknowledgment.

I must express my thanks to Larry Niven, David Brin and Eric Brown, who took the trouble to read and comment closely on drafts of this novel, and on the imagined universe it portrays: thanks to their input the quality of this work has been greatly enhanced. Thanks also to Arthur C. Clarke, Bob Shaw, Charles Sheffield, Joe Haldeman, and David Pringle for their words of praise and encouragement. Finally I owe a great debt of grat.i.tude to Malcolm Edwards, my editor at Grafton, for his patience, encouragement, and close attention to the development of this work.

1.

IT WAS WHEN THE FOUNDRY IMPLODED that Rees's curiosity about his world became unbearable.

The shift started normally enough with a thump on his cabin wall from the fist of Sheen, his shift supervisor. Groggily Rees pulled himself from his sleeping net and moved slowly about the jumbled cabin, grinding through his wake-up routines.

The water from the rusty spigot emerged reluctantly in the microgee conditions. The liquid was sour and cloudy. He forced down a few mouthfuls and splashed his face and hair. He wondered with a shudder how many human bodies this water had pa.s.sed through since its first collection from a pa.s.sing cloud; it had been dozens of shifts since the last supply tree from the Raft had called with fresh provisions, and the Belt's antique recycling system was showing its deficiencies.

He pulled on a stained, one-piece coverall. The garment was getting too short. At fifteen thousand shifts old he was dark, slim - and tall enough already and still growing, he thought gloomily. This observation made him think with a stab of sadness of his parents; it was just the sort of remark they might have made. His father, who had not long survived his mother, had died a few hundred shifts ago of circulatory problems and exhaustion. Suspended by one hand from the door frame Rees surveyed the little iron-walled cabin, recalling how cluttered it had seemed when he'd shared it with his parents.

He pushed such thoughts away and wriggled through the narrow door frame.

He blinked for a few seconds, dazzled by the shifting starlight... and hesitated. There was a faint scent on the air. A richness, like meat-sim. Something burning?

His cabin was connected to his neighbor's by a few yards of fraying rope and by lengths of rusty piping; he pulled himself a few feet along the rope and hung there, eyes raking the world around him for the source of the jarring scent.

The air of the Nebula was, as always, stained blood-red. A corner of his mind tried to measure that redness - was it deeper than last shift? - while his eyes flicked around the objects scattered through the Nebula above and below him. The clouds were like handfuls of grayish cloth sprinkled through miles of air. Stars fell among and through the clouds in a slow, endless rain that tumbled down to the Core. The light of the mile-wide spheres cast shifting shadows over the clouds, the scattered trees, the huge blurs that might be whales. Here and there he saw a tiny flash that marked the end of a star's brief existence.

How many stars were there?

As a child Rees had hovered among the cables, eyes wide, counting up to the limits of his knowledge and patience. Now he suspected that the stars were without number, that there were more stars than hairs on his head... or thoughts in his head, or words on his tongue. He raised his head and scoured a sky that was filled with stars. It was as if he were suspended in a great cloud of light; the star-spheres receded with distance into points of light, so that the sky itself was a curtain glowing red-yellow.

The burning scent called to him again, seeping through the thin air. He wrapped his toes in the cabin cable and released his hands; he let the spin of the Belt straighten his spine, and from this new viewpoint surveyed his home.

The Belt was a circle about eight hundred yards wide, a chain of battered dwellings and work places connected by ropes and tubes. At the center of the Belt was the mine itself, a cooled-down star kernel a hundred yards wide; lifting cables dangled from the Belt to the surface of the star kernel, sc.r.a.ping the rusty meniscus at a few feet per second.

Here and there, fixed to the walls and roofs of the Belt, were the ma.s.sive, white-metal mouths of jets; every few minutes a puff of steam emerged from one of those throats and the Belt tugged imperceptibly faster at his heels, shaking off the slowing effects of air friction. He studied the ragged rim of the nearest jet; it was fixed to his neighbor's roof and showed signs of hasty cutting and welding. As usual his attention drifted off into random speculation. What vessel, or other device, had that jet come from? Who were the men who had cut it away? And why had they come here...?

Again the whiff of fire. He shook his head, trying to concentrate.

It was shift-change time, of course, and there were little knots of activity around most of the cabins in the Belt as workers, grimy and tired, made for their sleep nets - and, a quarter of the Belt's circ.u.mference from him, a haze of smoke hovered around the foundry. He saw men dive again and again into the grayish fog. When they reemerged they tugged limp, blackened forms.

Bodies?

With a soft cry he curled, grasped the rope and sprint-crawled over the diffuse gravity wells of cabin roofs and walls to the foundry.

He hesitated on the edge of the sphere of smoke. The stench of burnt meat-sim made his empty stomach twist. Two figures emerged from the haze, solidifying like figures in a dream. They carried an unrecognizable, bloodied bundle between them. Rees anch.o.r.ed himself and reached down to help them; he tried not to recoil as charred flesh peeled away in his hands.

The limp form was bundled in stained blankets and hauled tenderly away. One of the two rescuers straightened before Rees; white eyes shone out of a soot-smeared face. It took him a few seconds to recognize Sheen, his shift supervisor. The pull of her hot, blackened body was a distant tugging at his belly, and he was ashamed to find, even at a moment like this, his eyes tracking sweat droplets over her blood-smeared chest. "You're late," she said, her voice smoke-deep as a man's.

"I'm sorry. What's happened?"

"An implosion. What do you think?" Pushing scorched hair from her brow she turned and pointed into the stationary pall of smoke. Now Rees could make out the shape of the foundry within; its cubical form had buckled, as if crushed by a giant hand. "Two dead so far," Sheen said. "d.a.m.n it. That's the third collapse in the last hundred shifts. If only Gord built strong enough for this d.a.m.n stupid universe, I wouldn't have to sc.r.a.pe my workmates off each other like so much spoiled meat-sim. d.a.m.n, d.a.m.n."

"What shall I do?"

She turned and looked at him with annoyance; he felt a flush of embarra.s.sment and fear climb in his cheeks. Her irritation seemed to soften a little. "Help us haul the rest out. Stick close to me and you'll be fine. Try to breathe through your nose, OK?"

And she turned and dived back into the spreading smoke. Rees hesitated for a single second, then hurried after her.

The bodies were cleared and allowed to drift away into the Nebula air, while the injured were collected by their families and gently bundled to waiting cabins. The fire in the foundry was doused and soon the smoke was dispersing. Gord, the Belt's chief engineer, crawled over the ruins. The engineer was a short, blond man; he shook his head miserably as he began the work of planning the rebuilding of the foundry. Rees saw how the relatives of the dead and injured regarded Gord with hatred as he went about his work. Surely the series of implosions could not be blamed on the engineer?

...But if not Gord, who?

Rees's shift was cancelled. The Belt had a second foundry, separated from the ruin by a hundred and eighty degrees, and Rees would be expected to call there on his next working shift; but for now he was free.

He pulled his way slowly back to his cabin, staring with fascination at the blood-trails left by his hands on ropes and roofs. His head seemed still to be full of smoke. He paused for a few minutes at the entrance to his cabin, trying to suck clean oxygen from the air; but the ruddy, shifting starlight seemed almost as thick as smoke. Sometimes the Nebula breezes seemed almost unbreathable.

If only the sky were blue, he thought vaguely. I wonder what blue is like... Even in his parents' childhood - so his father had said - there were still hints of blue in the sky, off at the edges of the Nebula, far beyond the clouds and stars. He closed his eyes, trying to picture a color he had never seen, thinking of coolness, of clear water.

So the world had changed since his father's day. Why? And would it change again? Would blue and those other cool colors return - or would the redness deepen until it was the color of ruined fleshRees pulled his way into his cabin and ran the spigot. He took off his tunic and scrubbed at his bloodstained skin until it ached.

The flesh peeled from the body in his hands like the skin from rotten fruit-sim; bone gleamed white - He lay in his net, eyes wide, remembering.

A distant handbell rang three times. So it was still only mid-shift - he had to endure another shift and a half, a full twelve hours, before he had an excuse to leave the cabin.

If he stayed here he'd go crazy.

He rolled out of his net, pulled on his coverall and slid out of the cabin. The quickest way to the Quartermaster's was along the Belt past the wrecked foundry; deliberately he turned and crawled the other way.

People nodded from windows and outdoor nets as he pa.s.sed, some smiling with faint sympathy. There were only a couple of hundred people in the Belt; the tragedy must have hit almost everybody. From dozens of cabins came the sounds of soft weeping, of cries of pain.

Rees lived alone, keeping mostly to his own company; but he knew almost everybody in the Belt. Now he lingered by cabins where people to whom he was a little closer must be suffering, perhaps dying; but he hurried on, feeling isolation thicken around him like smoke.

The Quartermaster's bar was one of the Belt's largest buildings at twenty yards across; it was laced with climbing ropes, and bar stock covered most of one wall. This shift the place was crowded: the stink of alcohol and weed, the bellow of voices, the pull of a ma.s.s of hot bodies - it all hit Rees as if he'd run into a wall. Jame, the barman, plied his trade briskly, laughing raucously through a graying tangle of beard. Rees lingered on the fringe of the milling crowd, anxious not to return to his desolate cabin; but the drink and laughter seemed to flow around him, excluding him, and he turned to leave.

"Rees! Wait..."

It was Sheen. She had pushed away from the center of a group of men; one of them - a huge, intimidating miner called Roch - called after her drunkenly. Sheen's cheeks were moist from the heat of the bar and she had cropped away her scorched hair; otherwise she was bright and clean in a fresh, skimpy tunic. When she spoke her voice was still scoured rough by the smoke. "I saw you come in. Here. You look like you need this." She held out a drink in a tarnished globe.

Suddenly awkward, Rees said, "I was going to leave-"

"I know you were." She moved closer to him, unsmiling, and pushed the drink into his chest. "Take it anyway." Again he felt the pull of her body as a warmth in his stomach - why should her gravity field have such a distinct flavor from that of others? - and he was distractingly aware of her bare arms.

"Thanks." He took the drink and sucked at the globe's plastic nipple; hot liquor coursed over his tongue. "Maybe I did need that."

Sheen studied him with frank curiosity. "You're an odd one, Rees, aren't you?"

He stared back, letting his eyes slide over the smoothness of the skin around her eyes. It struck him that she wasn't really much older than he was. "How am I odd?"

"You keep yourself to yourself."

He shrugged.

"Look, it's something you need to grow out of. You need company. We all do. Especially after a shift like this one."

"What did you mean earlier?" he asked suddenly.

"When?"

"During the implosion. You said how hard it was to build anything strong enough for this universe."

"What about it?"

"Well... what other universe is there?"

She sucked at her drink, ignoring the shouted invitations from the party behind her. "Who cares?"

"My father used to say the mine was killing us all. Humans weren't meant to work down there, crawling around in wheelchairs at five gee."

She laughed. "Rees, you're a character. But I'm not in the mood for metaphysical speculation, frankly. What I'm in the mood for is to get brain-dead on this fermented fruit-sim. So you can join me and the boys if you want, or you can go and sigh at the stars. OK?" She floated away, looking back questioningly; he shook his head, smiling stiffly, and she drifted back to her party, disappearing into a little pool of arms and legs.

Rees finished his drink, struggled to the bar to return the empty globe, and left.

A heavy cloud, fat with rain, drifted over the Belt, reducing visibility to a few yards; the air it brought with it seemed exceptionally sour and thin.

Rees prowled around the cables that girdled his world, muscles working restlessly. He completed two full circuits, pa.s.sing huts and cabins familiar since his childhood, hurrying past well-known faces. The damp cloud, the thin air, the confinement of the Belt seemed to come together somewhere inside his chest. Questions chased around his skull. Why were human materials and building methods so inadequate to resist the forces of the world? Why were human bodies so feeble in the face of those forces?

Why had his parents had to die, without answering the questions that had haunted him since childhood?

Shards of rationality glittered in the mud of his overtired thinking. His parents had had no better understanding of their circ.u.mstances than he had; there had been nothing but legends they could tell him before their sour deaths. Children's tales of a Ship, a Crew, of something called Bolder's Ring... But his parents had had - acceptance. They, and the rest of the Belt dwellers - even the sparkiest, like Sheen - seemed implicitly to accept their lot. Only Rees seemed plagued by questions, unanswered doubts.

Why couldn't he be like everyone else? Why couldn't he just accept and be accepted?

He let himself drift to rest, arms aching, cloud mist spattering his face. In all his universe there was only one ent.i.ty which he could talk to about this - which would respond in any meaningful way to his questions.

And that was a digging machine.

With a sudden impulse he looked about. He was perhaps a hundred yards from the nearest mine elevator station; his arms and legs carried him to it with renewed vigor.

Cloud mist swirled after Rees as he entered the station. The place was deserted, as Rees had expected. The whole shift would be lost to mourning; not for another two or three hours would the bleary-eyed workers of the next shift begin to arrive.

The station was little more than another cubical iron shack, locked into the Belt. It was dominated by a ma.s.sive drum around which a fine cable was coiled. The drum was framed by winch equipment constructed of some metal that remained free of rust, and from the cable dangled a heavy chair fitted with large, fat wheels. The chair was topped by a head and neck support and was thickly padded. There was a control panel fixed to a strut at one end of the drum; the panel was an arm's-length square and contained fist-sized, color-coded switches and dials. Rees rapidly set up a descent sequence on the panel and the winch drum began to vibrate.

He slid into the chair, taking care to smooth the clothing under his back and legs. On the surface of the star a crease of cloth could cut like a knife. A red light flashed on the control panel, casting sombre shadows, and the base of the cabin slid aside with a soft grind. The ancient machinery worked with a chorus of sc.r.a.pes and squeaks; the drum turned and the cable began to pay out.

With a jolt Rees dropped through the station floor and into the dense cloud. The chair was pulled down the guide cable; the guide continued through the mist, he knew, for four hundred yards to the surface of the star. The familiar sensation of shifting gravity pulled at his stomach like gentle hands. The Belt was rotating a little faster than its...o...b..tal velocity - to keep the chain of cabins taut - and a few yards below the Belt the centripetal force faded, so that Rees drifted briefly through true weightlessness. Then he entered the gravity well of the star kernel and his weight built up rapidly, plating over his chest and stomach like iron.

Despite the mounting discomfort he felt a sense of release. He wondered what his workmates would think if they could see him now. To choose to descend to the mine during an off-shift... and what for? To talk to a digging machine?

The oval face of Sheen floated before him, intelligent, skeptical and pragmatic.

He felt a flush burn up through his cheeks and he was suddenly glad that his descent was hidden by the mist.

He dropped out of the mist and the star kernel was revealed. It was a porous ball of iron fifty yards wide, visibly scarred by the hands and the machines of men. The guide cable - and its siblings, spread evenly around the Belt - sc.r.a.ped along the iron equator at a speed of a few feet each second.

His descent slowed; he imagined the winch four hundred yards above him straining to hold him against the star's clutching pull. Weight built up more rapidly now, climbing to its chest-crushing peak of five gees. The wheels of the chair began to rotate, whirring; then, cautiously, they kissed the moving iron surface. There was a b.u.mp which knocked the breath out of him. The cable disengaged rapidly, whipping backwards and away through the mist. The chair rolled slowly to a halt, carrying Rees a few yards from the trail of the cable.

For a few minutes Rees sat in the silence of the deserted star, allowing his breathing to adjust. His neck, back and legs all seemed comfortable in their deep padding, with no circulation-cutting folds of flesh or cloth. He lifted his right hand cautiously; it felt as if bands of iron encased his forearm, but he could reach the small control pad set into the chair arm.

He turned his head a few degrees to left and right. His chair sat isolated in the center of an iron landscape. Thick rust covered the surface, scoured by valleys a few inches deep and pitted by tiny craters. The horizon was no more than a dozen yards away; it was as if he sat at the crest of a dome. The Belt, glimpsed through the layer of cloud around the star, was a chain of boxes rolling through the sky, its cables hauling the cabins and workshops through a full rotation every five minutes.

Rees had often worked through in his head the sequence of events which had brought this spectacle into being. The star must have reached the end of its active life many centuries earlier, leaving a slowly spinning core of white-hot metal. Islands of solid iron would have formed in that sea of heat, colliding and gradually coalescing. At last a skin must have congealed around the iron, thickening and cooling. In the process bubbles of air had been trapped, leaving the sphere riddled with caverns and tunnels - and so making it accessible to humans. Finally the oxygen-laden air of the Nebula had worked on the shining iron, coating it with a patina of brown oxide.

The star kernel was probably cold all the way to its center by now, but Rees liked to imagine he could feel a faint glow of heat from the surface, the last ghost of star fire The silence was lanced through by a whine, far above him. Something glittering raced down through the air and hit the rust with a small impact a yard from Rees's chair. It left a fresh crater a half-inch across; a wisp of steam struggled to rise against the star pull.

Now more of the little missiles fizzed through the air; the star rang with impacts.

Rain. Metamorphosed by its fall through a five-gee gravity well into a hail of steaming bullets.

Rees cursed and reached for his control panel. The chair rolled forward, each b.u.mp and valley in the landscape jarring the breath from him. He was a few yards still from the nearest entrance to the mine works. How could he have been so careless as to descend to the surface - alone - when there was danger of rain? The shower thickened, slamming into the surface all around him. He cringed, pinned to his chair, waiting for the shower to reach his head and exposed arms.

The mouth of the mine works was a long rectangle cut in the rust. His chair rolled with agonizing slowness down a shallow slope into the depths of the star. At last the roof of the works was sliding over his head; the rain, safely excluded, spanged into the rust.

After pausing for a few minutes to allow his rattling heart to rest, Rees rolled on down the shallow, curving slope; Nebula light faded, to be replaced by the white glow of a chain of well-s.p.a.ced lamps. Rees peered up at them as he pa.s.sed. No one knew how the fist-sized globes worked. Apparently the lamps had glowed here unattended for centuries - most of them, anyway; here and there the chain was broken by the dimness of a failed lamp. Rees pa.s.sed through the pools of darkness with a shudder; typically his mind raced through the years to a future in which miners would have to function without the ancient lamps.

After fifty yards of pa.s.sageway - a third of the way around the circ.u.mference of the star - the light of the Nebula and the noise of the rain had disappeared. He reached a wide, cylindrical chamber, its roof about ten yards beneath the surface of the star. Rust-free walls gleamed in the lamplight. This was the entrance to the mine proper; the walls of the chamber were broken by the mouths of five circular pa.s.sageways which led on into the heart of the star. The Moles - the digging machines - cut and refined the iron in the pa.s.sageways, returning it in manageable nodules to the surface.

The real function of humans down here was to supplement the limited decision-making capabilities of the digging machines - to adjust their quota, perhaps, or to direct the gouging of fresh pa.s.sageways around broken-down wheelchairs. Few people were capable of more... although some miners, like Roch, were full of drunken stories about their prowess under the extreme gravity conditions.

From one pa.s.sageway came a grumbling, sc.r.a.ping sound. Rees turned the chair. After some minutes a blunt prow nosed into the light of the chamber, and - with painful slowness - one of the machines the miners called the Moles worked its way over the lip of the tunnel.

The Mole was a cylinder of dull metal, some five yards long. It moved on six fat wheels. The prow of the Mole was studded with a series of cutting devices and with handlike claws which worked the star iron. The machine's back bore a wide pannier containing several nodules of freshly cut iron.