by Stephen Baxter

When the silver woman first appeared, in the midst of the carnage of Culloden Moor, Angus Ban thought perhaps she was an angel.

The battle seemed already to have lasted a lifetime.

Since daybreak the Rebels had been drawn into a stern line facing the English Army; Angus, with the rest of the MacDonald Clan, stood at the left end of the thin tartan line. After a night of futile marching at the behest of Prince Charles and his staff the Clans were already sleep-deprived, already exhausted. Now the wind and sleet pounded their faces. And soon there came a deadlier rain from the Royal battalion guns.

The shots burst the bodies of men around Angus, scattering their limbs as if they were dolls.

Still the Rebels stood, waiting for orders from their Clan chiefs, enduring. The pipes' rant rose to a scream.

The Clan Chattan, to Angus's right, broke from the centre of the Rebel line. With their kilts pulled high to the groin and their white-cockaded bonnets jammed down over their brows, the Rebels ran with their bodies bent and their feet kicking at the sodden heather.

Musket fire exploded from the white-gaitered ranks of English troops.

The metallic smell of gunpowder -- and, soon, the butcher's-slab stench of blood -- drifted to Angus through the rain.

At last, through the mist and confusion, Angus heard the cry to advance from his own Clan chief, the MacDonald of Keppoch, his father. Angus raised his broadsword high, and with his dirk and target before him he ran forward, his feet pounding on the uneven, wet ground.

All around him Clansmen fell to English grape. Angus, to his horror, found himself treading on broken flesh.

When Turco donned her armour, the biocomposite material seemed to flow over her like a second skin, warm, embracing.

A Virtual of Earth hung before her, swollen and blue, rotating slowly. Anonymous machinery filled the darkness of the chamber beyond.

Moroz faced her. The blue light of Earth shone from his dome of forehead. Moroz was her controller. The two of them were alone here, at the heart of the Decoherence project, beneath the uninhabitable Oklahoma dustbowl.

Moroz handed her the pack containing the Decoherence switch. ''You know how this works, don't you?'' he asked. ''I don't know how much of your primer in quantum mechanics you took in. Every time a quantum system is faced with a choice, the world splits into two or more realities. The disentangling of the quantum realities takes a finite time, called a Decoherence ... That's the angle we exploit; that's what enables you to pass between the universes. All you have to do is activate the pack. You'll enter the mediator cosmos. And then you'll pass back into our universe, in some other timeframe -- ''

She fixed the pack to her chest. ''I've gone through enough briefings, Moroz.''

''I'll be with you,'' he said.

''No, you won't,'' she said sourly. ''A partial Virtual of you will be with me. And that's only so you can get a report back from someone you trust.''

She stepped up to the Virtual globe. She passed a gloved hand through the Pacific's blue belly; a trail of cubical crystals followed her silver fingers. ''Nice image.''

''Yeah. Real time, from Jap geo satellites.'' Moroz was gaunt, definite, around fifty. ''We show this to all our scouts. The last thing they see of their own timeframe before they leave. A kind of imprinting, a final reminder of what this is all about.''

''Imprinting, huh. Look, Moroz, I'm a grunt GI. I just want to complete the mission -- ''

''No.'' He shook his head, his face hard. ''This is more than just another assignment, Turco. Much more. Look at the planet, Turco.''

She looked.

The planet was visibly wounded.

There were patches of virulent green on the continents of the northern hemisphere. They were the reforestation projects, their extent hotly disputed by the contributing nations. The big continents of the south were filled with hot brown desert, their coasts lined grey with urban encrustation. Patches of grey in the seas, bordering the land, marked the sites of disastrous attempts to pump carbon dioxide into the deep oceans. Over Antarctica, laser arrays glowed red, labouring to destroy the tropospheric chlorofluorocarbons. In the north she saw the parallel contrails of the fleet of aircraft injecting chlorine-scavenging chemicals into the ozone layer. Shadows swam over the sunlit waters of the Pacific, cast by the big insolation-reducing parasols at the Lagrange-1 stationary point ...

''Even from here,'' said Moroz, ''even from geo, you can see how we're trying to fix the planet. To terraform the Earth. But we're failing.''

She shrugged; the biocomposite moved easily over her skin. ''Moroz, I know all this.''

''Do you?'' He stepped up to her, standing between her and the Virtual. ''You're going out there to save the human species, Turco; you and the other scouts. We need you to bring back the Omega Numbers. That's what you have to remember, to hang on to. Remember this image.''

''What is this, a pep talk? Let me go, Moroz.''

He stepped back from her. ''One more thing, Turco,'' he said. ''Don't get involved. Whatever you find, remember that. It's not your problem ...''

''Sure.'' She lifted her visor over her head, shutting out the image of Earth.

''Godspeed,'' Moroz said.

She closed the switch on her chest. Blue quantum threads coalesced around her body.

The Clansmen roared Gaelic oaths. They feinted attacks, hoping to draw the Royal troops forward. But the English stood their ground and cut the Highlanders down where they stood, with virtually no cost or risk to themselves.

Angus Ban was an educated man of twenty-three; the previous summer, of 1745, had seen him matriculate from St John's College, Cambridge. So he had enough detachment to be able to interpret the patterns of the battle around him. In fact he felt a sense of dislocation in time: for surely the disciplined formation of the English represented the military methods of the future, while the Rebels -- with the wild charge their only tactic -- were a failing relic of history.

And yet, despite all his education and understanding, he ran with the rest, roaring defiance in Gaelic and French at the English muskets' bark, and letting humiliation turn his blood to fire.

As he approached, the English line resolved into individuals. He picked out a Tommy-Lobster, and charged towards him. This was a squat fellow, with the blunt features of a farmer. His scarlet coat was cuffed with regimental colours, his black tricorn was pushed down over his square head, and his thigh-length gaiters were caked with thick Scottish mud.

The soldier took a fresh cartridge of grape and bit savagely into it, releasing a dribble of powder to prime his pan. Angus saw teeth and tongue coated with the black powder.

The Tommy-Lobster's eyes met Angus's, and Angus saw fear and determination there. This is the man who will kill me, Angus thought suddenly.

Angus Ban raised his broadsword. It felt immensely heavy.

The soldier sighted along his musket.

The silver woman appeared.

She arrived a few paces before Angus, as suddenly as if through a trapdoor in the ground. She stumbled on the blood-soaked heather. She was coated in a suit of tight, flowing armour, and her face was hidden by a featureless visor.

The Lobster's musket flashed.

The grape cartridge slammed into the silver woman's right shoulder blade. She was spun about; she fell on her back, at Angus's feet.

Angus, astonished, stared down at her. The silver suit was bright amid the blood-soaked mud and tartan. Could this be an angel? And yet no angel would be felled by grape.

He looked up. The Lobster was lost in the smoke. All around Angus the Rebel lines were breaking up: kilts were raised once more, but this time in retreat.

Already, the battle was nearly done. Nearly lost.

Angus, acting on impulse, dropped his target. He knelt, grabbed the silver woman by the scruff of her neck, and dropped her over his shoulder.

He turned and fled Culloden Moor, with the long limbs of the silver woman dangling around him.

Turco opened her eyes.

She was lying on her back, in darkness. She waited for the visor's IR imaging system to kick in.

It didn't.

She raised her hands to her face (no, her left hand only; her right arm from the shoulder down was stiffened, immobilised within the biocomposite suit).

Her visor was gone.

Panic hit her now, shocking her to alertness. Using her left arm she struggled to a sitting position. Her right shoulder sent her echoes of pain, filtered through the suit's biomedical systems.

She scraped backwards on her butt. The floor was gritty and cold, and mud worked under her fingernails. Her back collided with a crude wall. She felt stone, sod, heather compacted together. She was in a hut, then. A hovel.

Impressions of this time, this place, crowded in on her. The air was cold, damp. The hut stank -- of stale urine, of rotting heather, of burnt peat. Her eyes started to adjust; shapes loomed in the darkness.

She recalled drifting, for an unmeasured time, in the mediator cosmos. And then --

Dimly she remembered smoke, noise, the stink of gunpowder, an instant of explosive pain. She'd been shot. Christ. My first jaunt, and I'm shot already.

She tried to check her status. The biocomposite of the suit was unbroken and had attenuated the impact, and interceptor molecules in her bloodstream would keep her free of infection until she got home. She felt dizzy, oddly elated: side effects of the anaesthetics her suit was pumping into her shoulder.

Maybe volunteering for this project hadn't been such a smart idea after all.

She heard breathing.

A form, over there, on the opposite side of the hut: a pale face, bearded, dimly visible over dark clothing. White legs glowing like bones in the chinks of light from the broken walls. A skirt of some kind -- no, a kilt?

Black eyes, fixed on her.

Her good hand flew to her waist, her chest. -- But her laser crystal was gone -- as was the chest pack containing her Decoherence switch.

Tentatively she raised her good arm, listened to the soft whir of the suit's exoskeletal multipliers. She assessed the distance between herself and the stranger, visualised the moves she would make to take him --

He said, ''Do not fear. I do not intend to harm you.''

Lightly accented English. And -- civilised. Even educated.

Turco hesitated.

The man raised his empty hands. ''We are safe here. The night has fallen, while you slept. This hut is abandoned, overgrown by the heather; from without it will appear as no more than a hummock, in the foreign eyes of the Lobsters.''

''You took my visor. And other materiel.''

''At first I thought you were an angel ... But a woman, dropped from nowhere into the hell that was Culloden this morn, is a no less remarkable sight.''


''I am Angus Ban,'' the boy said. ''Younger son of Alexander MacDonald, of Keppoch.''

''Angus Ban,'' she repeated. ''My name's Turco. UN Special Forces. Uh, United Nations.''

Moroz's Virtual voice whispered through the bones of her skull. Got it. You're in Scotland, Turco. It's 1746. Spring. Scene of the rout by English troops of the army of Clansmen raised by the exiled Charles Stuart, the so-called Bonnie Prince. The causes of the Rebellion --

Bonnie Prince Charlie, she thought. Christ.

But at least, on Culloden Moor, there would be plenty of raw material for her search.

Angus frowned, looking hunted. ''Are you a Lobster after all, then, girl? United Nations. That's no regiment I've heard of.''

Automatically she analyzed his tone of voice. Light, feverish. She saw his pallor, his jerky movements. Classic shock symptoms.

''No regiment, Angus. I'm not even English.'' She considered. The sims hadn't prepared her for this kind of situation. Well, Angus was no fool; and she might be able to gain his trust. She had to get her equipment back; it would be easier if he helped. ''I'm a time traveller. I've come from the future. From the year 2073. Do you understand me? I've come back three centuries through time ...''

Angus nodded gravely. He didn't seem to find the concept impossible to accept.

Or maybe it was just the shock.

She was feeling dizzier, dull. It was getting harder to think. The suit was doing its best to keep her functioning, but she was going to need sleep soon.

She had a choice to make. Trust Angus. Or kill him now.

He could have killed her already, while she lay unconscious.

She decided to give him the benefit of the doubt.

''Give me my tools, Angus,'' she said.

For a moment their eyes met, and she saw calculation in his face.

''Believe me,'' she said evenly, ''I am capable of killing you, even without my equipment. I'll do it without hesitation, Angus Ban.''

The tension stretched between them.

Then Angus seemed to relax; something of the tautness went out of the set of his bare limbs.

He dug into the ground. He'd buried the visor, with the Decoherence pack and laser crystal inside it, under a shallow layer of earth. Now he brushed off the equipment and handed it to her.

He said, ''Why did you come? Simply to save me from a Lobster's cartridge? For you did, and that is why I dragged you from the Moor, abandoning my Clansmen.''

She seemed to have made her decision. ''That was a happy accident, Angus. Happy for you, anyhow. My journey's random ... but it is omegatropic. I am seeking the Omega Numbers.''


''The truth at the end of the universe.''

He smiled grimly. ''What truth will you find on Culloden Moor?''

She grunted. ''Have you any food?''

''I ... no.''

Turco placed her visor on the ground, so that it formed a shallow bowl. ''Get me some heather.''

Angus hesitated. ''We would be ill-advised to start a fire.''

''Not for a fire. Food. You'd like to eat, wouldn't you?''

He squatted at the cave's entrance, silhouetted against the blue-black sky. ''But -- heather?''

''Angus. Don't argue. Trust me.''

He shuffled out of the cave.

Don't get involved, Turco.

''Shut up,'' she whispered.

You'll get yourself killed ...

Angus Ban returned with a bale of moist heather, bundled into a fold of his plaid. Turco fed crumbled fragments of the heather into the upturned visor. The device secreted bioengineered enzymes, and soon a brownish liquid was pooling in the upturned faceplate.

She held up the visor. ''Here. Drink.''

He pushed away fragments of heather and stared into the liquid doubtfully. Then he raised the visor like a huge cup and took a healthy draught. ''Good Lord,'' he said. ''It tastes of chicken!''

Turco took the visor and drank.

''The soldiers of your century are exceedingly well-equipped, Turco.''

''Yeah. Soldiers are expensive items in my time. An investment worth protecting.''

She had the visor clean itself, donned it. She let herself slump down to the cold ground. She couldn't put off sleep much longer.

Angus said, ''Are you cold? I can spare some plaid, if you wish.''

The thermostatic filigree of the suit encased her. ''Thanks, Angus. I'm fine. Try to sleep. Wake me if the Lobsters come.''

Thomas Lobster. Clannish slang for the redcoated English troops, who --

''Shut up, Moroz.''

Angus stared at her.

The data trickle whispered to silence. She let sleep claim her.

Angus Ban couldn't rest. Not on the night of Culloden.

He got to his feet in the dark, and stepped quietly from the hut. Turco, the silver woman from the future, did not stir.

He walked through darkness to Culloden Moor. The land, black and treeless, fell away before him. The mountains were a saucer-rim around him; he felt as if he were suspended between a dome of bruised purple and the night-darkened sky.

He got to his belly, his body pressed flat against the muddy heather, his white Stuart cockade hidden beneath his plaid.

The English had lit fires in their encampments beyond the Moor; the flames cast fragments of muddy light over the battlefield. The dead lay where they had fallen, and the cries of the wounded rose like smoke from all around the field. Royal troops stalked across the Moor, stilling the cries with bayonet thrusts. Angus heard the troops' laughter. One man, a burly private, did a little jig for the benefit of his mates, splashing in blood pools.

His father could be down there: alive still, a toy for these barbaric English. Angus buried his face in the moist, cold heather.

... Turco. Turco, damn you. Wake up.

''... Huh? Did I sleep?''

Damn right.

Her bladder was full, she found; she released it, and felt the warm gush of liquid into her catheter.

How's the arm?

She tried to move it. ''Stiff. Numb. The damn thing's broken. What do you expect? ... Ah, the hell with it. Let me sleep, Moroz.''

You can't afford to sleep.

''Maybe I should just come home. I'm wounded, Moroz.''

No. What you're doing out there is too important. You have to remember that. You have to make sacrifices ...

She ascended towards full consciousness.

The hut was very quiet.

Adrenaline pumped into her system, augmented by the suit.

She rolled on her back, reaching for her laser crystal.

Angus Ban was gone.

He tried to gather his resolve. He should go once more to the field, his broadsword raised in defiance --

''Well. Look what I've found. A fresh, ripe humblie, a-waiting to be plucked.''

Angus rolled onto his back. The Lobster stood over him, bayonet ready, powder-stained teeth glinting.

Angus reached for the basket-hilt of his broadsword.

''Angus. Stay where you are. Stay flat, you asshole!''

The whisper came from Angus's left. Both he and the Royal looked that way, startled.

A spot of red light, oddly speckled, appeared at the Lobster's throat. He gurgled, as if choking. Another spot shone over the centre of his coat. The Lobster stared down at Angus, looking surprised, and fell back into the heather.

Angus Ban staggered out of the heather, embarrassed. ''You did not need to do that,'' he hissed. ''I would have -- ''

''Shut up,'' Turco said. Her visor hid the square jaw, the cropped hair he remembered. She fingered the open mouth of the Lobster. Then she held her left hand out before his eyes, fingers spread.

Angus frowned. ''What are you doing?''

She turned her hidden face towards him. ''Robbing this dying man of his soul. Seeking the Omega. It's why I'm here, Angus.''

She jabbed a finger into each of the soldier's eyes. Dark fluid spurted over her silver gloves and ran down the soldier's cheeks. There was a purple flash, inside the soldier's skull; for an instant his head was transformed into a grotesque lantern.

Turco looked at Angus, and seemed to register his look of horror, of disgust. She touched a box on her chest. A blue glow gathered around her limbs. ''I'm done here, Angus. I ---''

There were shouts, rising from the Moor. Angus turned. Soldiers were pointing at them; Angus heard the clink of muskets.

''We have been espied,'' he said. ''What shall we do? ... Turco?''

She was gone. The blue glow had dispersed. The Lobster's eyeless corpse slumped against the ground, as if boneless.

Angus gathered up his grubby plaid and stumbled away into darkness.

Turco drifted, weightless. The biocomposite suit had turned semi-rigid, shielding her from the vacuum. She could feel the cool flow of oxygen over her face.

There was no Earth. No sun. Even the stars were gone, save for the thinnest scattering of dim lamps.

This was the mediator cosmos. In this inert alternate universe, the constant of gravity was a few per cent greater than at home. Stellar fusion rates were higher; most of the stars here had burned out a billion years ago. The mediator cosmos was used by the Decoherence project as a holding place; from here she could step back into her own universe, at different points of the timeline.

... There was something here with her. She monitored a new data structure inside her suit's stores: she recognised lingering shards of

memory of a Sussex childhood, of brutal adult years in the English Army. Fear, shock.

This was the essence of the soldier she'd destroyed, downloaded into her datastores.

The personality remnant quickly lost its coherence. Fragments of memory, green like leaves, tumbled away into the emptiness around her, dwindling, frightened, regretful.

She felt a savage sense of loss. She allowed herself to mourn, briefly, for another vanished life.

She checked her stores. A little data, raw and uninterpreted, remained. The data fragment could be more precious than life itself: it was a glimpse into another universe. She archived the data, carefully.

She opaqued her visor. She saw a reflection of her own face, by the light of an internal lamp. The suit was a warm, comfortable shell around her. She closed her eyes.

The smells of old Scotland -- the feel of her fingers as they slid into the eye-sockets of the English soldier -- receded from her. Here, alone in all this universe, she felt calm, clean. Alone. It was a nice thought. No people; no death.

She tried to shut Angus Ban out of her head.

Drifting, she thought about Omega Numbers.

In the twenty-first century, physics was unified, unchallengeable, a wonderful monument to human reason. A monument erected on a planet going sour.

But there were difficulties. The Omega Numbers.

The Omega Number whose existence had been the first to be deduced expressed the probability that a computer program would halt if its input consisted of a random string of binary numbers. The number included the data content of all possible finite computer programs. It held, among other things, proofs of Fermat's Last Theorem and the Goldbach Conjecture.

That Number would be worth knowing.

But it was algorithmically incompressible: apparently random, non-computable. That is, it was impossible even in principle for its value to be determined.

Some of the fundamental constants of physics -- such as the ratio of the neutrino's mass to the electron's -- had turned out, under the complicated unified theories, to be non-computable.

The non-computability of the Omega Numbers blocked progress in physics. And therefore in applied science, in technology.

Science had promised a ladder off the failing Earth, and to an infinite future. But because of the Omega Numbers the ladder had terminated, after a couple of rungs. Earth, choking to death, had turned into a trap.

So the Omega Numbers had to be determined, non-computable or not.

It turned out there was a way.

Computability was linked to the operation of computers -- and so to the physical structure of the universe. But it was possible to imagine other universes: cosmoses so different that the Omega Numbers might be easily computable, while the everyday sums of simple arithmetic weren't ...

And so scouts, Turco and her colleagues -- conscripts and volunteers alike -- were sent to the places where the walls of the universe were thinnest. Where glimpses of differently-computable universes might be obtained.

It turned out that the thin walls were places where death walked

Through the windows of a million deaths, the Decoherence project was trying to peer into different universes, to catch glimpses of the Omega Numbers.

Angus Ban, alone, did not dare return to the hut. He ran across the heather, his lungs straining at the cold air.

He found a cave, a dark mouth in the hill side. He crawled inside.

There was a potent stink: cat, and a few earlier occupants. As he crawled, he found his hands sinking into darkened heaps of droppings. But the stuff was dry and stale. He'd not be disturbed; not by animals of the four-legged sort, anyway ...

He set up a length of stick at the back of the cave and lit it with a flint; it was a resin-heavy fir twig, and it burned like a candle, giving a smoky yellow light.

He was cold. Would these cat-droppings burn? But even if so, surely the stink would bring the Tommy-Lobsters at a canter.

He would be better advised to wait here until light. Perhaps then he could steal some food, from a croft or even from the Lobsters. And, beyond that, he must consider how he could reach safety, away from this hellish place.

He wondered what had become of Turco, the silver warrior.

There was a noise outside the cave mouth, a soft snuffling.

He doused his candle, and sat fearfully in the dark, hugging his knees.

After a few moments, the intruder -- animal or human, he could not say -- receded.

After that he dared not light his resin candle again. He hugged his plaid tight around him, and huddled in the dark.

Turco remembered days in the streets of Liverpool and Houston and Naples ... standing in full body armour, with enough firepower to raze half a city ... and yet helpless to act in the face of men and women who, driven by ethnic and religious tensions older then Culloden, hurled ripped-up paving slabs at her, and would have clubbed each other to death with their bare hands if she allowed them.

She'd signed up for the Decoherence project to escape from that. Maybe, naively, she'd imagined that the past -- and perhaps the future -- couldn't be as foul as her own timeframe, that world wrecked by humanity, by that insane coupling of antique primate imperatives with the fever-dreams of science.

But the Decoherence project had made her omegatropic. She was drawn to death. And the long history of mankind, of Earth itself, was littered with death.

If Culloden Moor was an example, she had no escape.

She drifted in alternate space, considering.

Her path during this mission would form a ragged stitching between the two universes, the mediator cosmos and her own, back and forth. Right now she could go back where she'd come from: back to that bloody Scottish hill-side. Or forward, somewhere else. But if forward, she'd have no control.

She thought of blood-soaked heather. Culloden had been hideous. But her next stop could be worse.

She might be drawn to one of the great extinctions, such as the K/T boundary at the end of the Cretaceous: sixty-five million years into the past, in the aftermath of the Chicxulub impact. The angiosperm had been almost destroyed: no trees, no plants. There was searing heat, earthquakes, tsunamis, wildfires all over the planet, skies full of dust, months of cold ...

Decoherence scouts were drawn to such timeframes as moths to flame. They were usually lethal.

Back, she decided.

She touched her chest-pack.

She emerged into darkness.

It wasn't hard to track Angus's path.

Turco entered the cave, multidomain sensors livid before her face. The cave was about the size of a small car. She raised her visor. The cold air of the Highland night swept across her face and cheek; there was a musty, animal smell.

There was something at the back of the cave, in the dark. Thin, shivering, huddled on itself. Watching her.

She fingered her laser crystal. ''Angus?''

She heard a shudder of relief in his voice. ''Turco? Is it truly you?''

''Yes, damn it. It's me.''

She crawled into the cave and set up a small lamp.

Squatting, he came towards her, out of the foul-smelling shadows at the rear of the cave. He was streaked with stale dung, and he was shivering.

''For God's sake, Angus,'' she said. ''You really aren't a soldier, are you?''

''I would not claim to be.''

She let Moroz whisper random fragments of post-Culloden history into her ear. This is one hell of a timeframe, Turco. Some captive rebels were taken to London and -- in public -- hanged, and cut down alive; their bowels were hauled out and burned before their eyes, before final decapitation ...

Angus leaned against the wall, spreading his kilt over his lap. His eyes were bright in the flame's light. ''Futurity must be marvellous,'' he said, his voice hoarse with the cold. ''I wish I could see it. Perhaps you have circled the globe, in the course of your service. Perhaps there are wars on the Moon or on the sun, in the twenty-first century.''

She grunted. ''I'm afraid we're still trying to resolve our differences on Earth, Angus.''

''But with such equipment, such weapons as yours, surely any conflict could be settled in a snap.''

''It's not so simple. Guns don't always help.''

''Still, with your remarkable light-gun, you could expel the soldiers of the German King of England from the Highlands in a trice -- now, and forever more.'' He seemed to be trying to inspire her with his vision. ''Charles Stuart would tear up the Act of Union in the streets of Edinburgh, and -- ''

In the winter of 1746 the Highlanders starved. Families took to following the English soldiers on their missions of destruction, begging scraps of cattle gut and green hide, which they boiled for food. They were shot by the soldiers, for diversion and for wagers --

''That's not why I'm here, Angus. This is a special assignment. Scientific. They send soldiers because we're best equipped to survive, in hostile and unpredictable circumstances.''

''You said you are seeking numbers: magical, or sacred.''

''Yes. Numbers from beyond the walls of this universe ... I am seeking gateways to other universes.''

Angus smiled. ''It is a charming notion.''

She grimaced. ''Is it?''

''Where are these gateways?''

''Where people die. Wherever life is destroyed, in waves, on large scales ...''

Mind -- life itself -- was not embedded solely in one cosmos. Consciousness was a quantum process; the link between mind and body was a deep expression of quantum physics.

The walls between the alternate quantum realities were resilient, but thin. And -- where life was created, or destroyed, in waves -- there the walls could break down.

The grisly history of Earth, overlaid with war and extinction, was pocked with many such places.

''Then I understand why you were brought to Culloden,'' Angus said grimly. ''Yours is an unenviable mission, Turco.''

She shrugged. ''I'm beginning to think so.''

Through death to life, Turco, Moroz whispered. Remember that.

Angus went out to find more heather.

Turco slumped against a wall, still weak.

Moroz nagged her.

What are you doing, Turco? You can't be planning to saddle yourself with this half-educated kid. What are you going to do, escort him all the way home?

''Shut up, Moroz ...''

A cry -- quickly muffled -- startled her to full wakefulness.

Sensor systems fizzing, she crawled towards the cave mouth.

A musket snout greeted her. ''Out you come, lady. Don't try any sorcery, or it will serve your young Rebel friend the worse.''

Holding her hands away from her body she moved out of the cave. She straightened up. Three redcoats: the one whose musket was trained on her; another holding Angus's arms behind his back; a third with a bayonet-blade at Angus's throat.

Options cascaded through Turco's mind.

''Take it easy, Angus.''

''I'm sorry.'' There was a trickle of blood at the boy's neck; the mud on his bare legs was smeared by a fresh flow of urine.

''It's okay, Angus. You've nothing to be ashamed of. Just stay still; I'll get you home.''

Home? Get out of there, Turco. Don't get involved. Just get out of there.

The soldier facing her -- a corporal, by the look of his shoulder flashes -- ran his eyes over her body, speculating. Roughly he pushed her visor back over her head, exposing her face. She felt naked; she had a feeling of sudden, shocking immersion in this timeframe. She could see the dirt in the pores of the corporal's nose and cheeks, smell rum and meat on his breath. ''Now then,'' he said softly. ''Now then, indeed.''

Accent derives from Suffolk, England ...

''Give me your fancy musket, miss. And don't make a performance about it.''

Moroz whispered, Listen, Turco. This is one hell of a timeframe. You really, really don't want to get stranded here. After Culloden the victorious English will destroy the Highlanders' way of life, systematically. The glens will burn from the firths to the hills. Murder, rape and robbery by the troops will become commonplace --

She lifted her hand towards the Decoherence switch at her chest.

Angus somehow understood what she was thinking. ''Go, Turco,'' he hissed. ''Get away from this English hell.''

''Come on, pretty lady,'' the corporal said. ''I'm not a patient man.''

The gaols will be filled. Are you listening to me, Turco? The Highlanders' cattle will be driven from the hills, for sale to English farmers. At last the jurisdiction of the Clan chiefs will be abolished, and even the wearing of tartan outlawed. The Highlanders will starve ...

''Some reward for their romantic Rebellion.''

Moroz babbled in her ear. You don't need this, Turco. This isn't your argument. Get out of there. Remember your goals. You aren't out there to be a hero. You're not out there to help figure out some abstruse bit of physics, to earn yourself a footnote in some academic paper. The physics is only a means to an end. We have to find a way to get off the planet, spread to other worlds in large numbers, and --

She whispered, ''And then what, Moroz? What's the purpose of it all? To keep on spreading, like a plague?''

Cynical for a grunt, aren't you? Hell, I don't know. Maybe there is no purpose. But we can't stop now. If we try to, we'll die. You have to see that, Turco. You have to hold on to that ...

She looked at Angus. ''No. No, it's not enough, Moroz. Maybe it never was.''

Slowly, with every movement obvious, she handed her laser crystal to the corporal. She let her finger slide discreetly over its barrel, adjusting it to lowest power.

You're a damn fool, Turco.

The corporal fingered the crystal, poking grubby fingers at the firing button. Turco watched, hoping he'd blow his stupid head off.

He said, ''We saw what you did to Jack Martin. Above the battlefield. With your fingers.''

She made her expression as hard and unyielding as she could. ''And?''

He jammed the laser crystal into her left eye and pressed the firing stud.

Ruby light.

She heard a pop. Streamers of blood erupted into her vision, laced with specks of dark matter. The red glare flickered out, leaving the world a mess of blood and burnt retina fragments.

The back of her eyeball had exploded.

With an exoskeletal whir her left arm lifted. She clubbed the corporal; she felt the crunch of bone under her reinforced forearm.

She heard a scream of defiance, a musket shot. From out of the bloody fog, Angus's face loomed at her. There was a hole in his shoulder; bits of bone had burst out through charred plaid. ''Go, angel!'' He slammed his palm against the switch on her chest.

Decoherence switches were designed to be simple to operate.

The ground shuddered beneath her. Quantum functions -- her links to this slice of spacetime -- sparkled, like blue threads.

Angus was staggering, falling. She grabbed him.

Turco, for Christ's sake. Leave him --

Together, they fell away from gravity.

In weightlessness he struggled like a beached fish. She could feel his chest heaving, convulsively, seeking oxygen, in the vacuum of the mediator cosmos.

You're crazy, Turco. You can't save him.

''I don't care.'' She scrabbled at her chest pack, resetting it.

I'll get you back to Scotland. But you'll have to --

''No. Not back there.''

Then where? Forward? Are you crazy, Turco?


You're making a life choice here, Turco. The damn system's not designed for a passenger, for Christ's sake. I don't know if I can get you home again.

''A life choice. Yeah. Moroz, I'm done with this, with death and dying.''

But you're omegatropic. Even if you go forward, you're still seeking out death. You might end up at an extinction boundary. Don't you understand that? And what will you do with Rob Roy then?

''Shut up, Moroz.''

She closed the switch.

Coarse sand under her back. Her injured shoulder ached. The sun overhead was hot, harsh, immediate. Her throat and chest hurt as she dragged at the air; the oxygen content seemed low.

She looked out through her left eye. It was like seeing through a fishbowl filled with blood-laced water. Maybe she'd have to rig up a patch.

She sat up. No plants, no animals. The land was a plain. Maybe twenty yards away, a sea lapped. Perhaps a lake.

A terminal beach. Far future, maybe. A ruined Earth. Eco-collapse? A nuclear war? ... Or some horrific extinction episode of the past?

Moroz was silent. Maybe he was disabled, or had abandoned her.

Her proximity sensors told her that nothing was moving for many hundreds of metres around her. No communications, on any wavelength. We're safe, then. She waited for the suit to figure out where it was; she imagined its tiny imbedded sensors taking solar spectra, atmospheric traces, magnetic field declinations.

Beside her, Angus lay on the sand, face down. He was convulsing, as his lungs worked at the thin air. Blood seeped from his shoulder and soaked into the sand.

With her good arm she turned him over, and cradled his neck in the crook of her elbow. His shoulder was a bloody mess. His mouth opened and closed, like a fish.

She fit her visor over Angus's head. His racked breathing subsided, as the visor fed him oxygen.

One-handed, she began to strip off her suit. Briskly she pulled Angus's bloody plaid off his unresisting body, and wrapped the biocomposite material around him. It would disinfect and stabilise him -- keep him alive -- but eventually she was going to have to dig out that grapeshot for him.

His eyes flickered open. ''Turco?'' His voice was weak, and muffled by the visor.

''Yes, Angus. I'm here.''

He glanced around. ''We are far from Culloden Moor,'' he whispered.

''Yes. Do you want me to take you back?''

''I am dead there, Turco. The English have killed me ...''

''Yes,'' she said. If she took him back, he'd die for sure. Probably the medicine of 1746 couldn't help him anyhow. But that was academic; the English troops would just leave him to die on the moor. Or bayonet him for sport ...

''I would stay with you,'' he whispered. ''Wherever we are.''

... Data whispered into her skull from the non-sentient datastores.

She smiled.

''Are we in futurity, Turco? Are we in the twenty-first century?''

''No. This is the deep past: an ancient Europe, five hundred million years before your birth, Angus.''

This was the end of the pre-Cambrian era. Not a burnt-out future, but a rich past. The land was still empty, but the seas and tidal pools were bursting with life, with the greatest explosion of evolutionary diversity the biosphere would ever produce.

She was omegatropic. But this time she'd been drawn to a place of creation, not culling: a place where life entered the universe, in great waves.

She pulled Angus's kilt around her shoulders, and picked up the Decoherence pack. She walked down the shallow beach towards the sea. There were no trees here, no shelter. No land animals. No life at all on land, in fact. But in the oceans there were fish, worms, brachiopods, snails.

She grinned. A sea food diet.

They could survive here, at the dawn of everything, on this unscarred Earth. Just the two of them, two battered relics washed up on this primeval beach, supporting each other as best they could.

Behind her, Angus was trying to sit up. He called, ''Are we still searching for the truth, Turco?''

''I think perhaps we've found it, Angus.''

She took the Decoherence pack, and hurled it into the sea.

They would need shelter, and fresh water. She walked back to Angus, making plans.

LSFF:s hemsida