Permutation City

the skyscraper were motionless; not merely stationary with respect to the ground, but frozen in every detail. The wispiest tendrils at the edges, presumably vulnerable to the slightest breeze, remained undisturbed for as long as he studied them. The shape of every cloud seemed flawlessly natural—but all the dynamism implicit in the wind- wrought forms, compelling at a glance, was pure illusion. Nothing in the sky was changing.

For a moment, he was simply bemused by this whimsical detail. Then he remembered why he’d chosen it.

Kate had vanished. She’d lied; she hadn’t cloned herself at all. She’d moved to Carter’s city, leaving no other version behind.

Leaving him—or half of him—alone.

The revelation didn’t bother him. On the skyscraper, nothing ever did. He clung to the wall, recuperating happily, and marveled at what he’d done to heal the pain. Back in cloud time, before he’d always been descending.

He’d set up the environment as usual—the city, the sky, the building—but frozen the clouds, as much to simplify things as to serve as a convenient reminder.

Then he’d mapped out a series of cues for memory and mood changes over fifteen subjective minutes. He’d merely sketched the progression, like a naive musician humming a melody to a transcriber; the software he’d used had computed the actual sequence of brain states. Moment would follow moment “naturally”; his model-of-a-brain would not be forced to do anything, but would simply follow its internal logic. By fine-tuning that logic in advance and loading the right memories, the desired sequence of mental events would unfold: from A to B to C to… A.

Peer looked over his shoulder at the ground, which never grew closer, and smiled. He’d dreamed of doing this before, but he’d never had the courage. Losing Kate forever—while knowing that he was with her—must have finally persuaded him that he had nothing to gain by putting it off any longer.

The scheme wouldn’t slip his mind completely—he could vaguely remember experiencing exactly the same revelation several times before—but his short-term memory had been selectively impaired to limit the clarity of this recursive false history, and once he was distracted, a series of free associations would eventually lead him back to exactly the state of mind he’d been in at the cycle’s beginning. His body—with respect to every visible cue in the environment—would also be back where it had started. The ground and sky were static, and every story of the building was identical, so his perceptions would be the same. And every muscle and joint in his body would have recovered perfectly, as always.

Peer laughed at his cloud-self’s ingenuity, and started to descend again. It was an elegant situation, and he was glad he’d finally had a cloud-reason to make it happen.

There was one detail, though, which he couldn’t focus on, one choice he’d made back in cloud time which he seemed to have decided to obscure from himself completely.

Had he programmed his exoself to let him run through the cycle a predetermined number of times? ABCABCABC… and then some great booming DBF breaking through the sky like the fist of God—or a tendril of cumulus actually moving—putting an end to his perpetual motion? A grappling hook could tear him from the side of the building, or some subtle change in the environment could nudge his thoughts out of their perfectly circular orbit. Either way, experiencing one uninterrupted cycle would be the same as experiencing a thousand, so if there was an alarm clock ticking away at all, his next cycle—subjectively—would be the one when the buzzer went off.

And if there was no clock? He might have left his fate in external hands. A chance communication from another Copy, or some event in the world itself, could be the trigger which would release him.

Or he might have chosen absolute solipsism. Grinding through the cycle whatever else happened, until his executor embezzled his estate, terrorists nuked the supercomputers, civilization crumbled, the sun went out.

Peer stopped and shook his head to flick sweat out of his eyes. The sense of deja vu the action triggered was, presumably, purely synthetic; it told him nothing about the number of times he’d actually repeated the gesture. It suddenly struck him as unlikely that he’d done anything as inelegant as running the cycle more than once. His subjective time closed up in a loop, rolled in on itself; there was no need to follow the last moment with an external repetition of the first. Whatever happened— externally—“afterward,” the loop was subjectively seamless and complete. He could have shut himself down completely, after computing a single cycle, and it would have made no difference.

The breeze picked up, cooling his skin. Peer had never felt so tranquil; so physically at ease, so mentally at peace. Losing Kate must have been traumatic, but he’d put that behind him. Once and for ever.

He continued his descent.

21 (Remit not paucity) JUNE 2051

Maria woke from a dream of giving birth. A midwife had urged her, “Keep pushing! Keep pushing!” She’d screamed through gritted teeth, but done as she was told. The “child” had turned out to be nothing but a blood- stained statue, carved from smooth, dark wood.

Her head was throbbing. The room was in darkness. She’d taken off her wristwatch, but she doubted that she’d been asleep for long; if she had, the bed would have seemed unfamiliar, she would have needed time to remember where she was, and why. Instead, the night’s events had come back to her instantly. It was long after midnight, but it wasn’t a new day yet.

She sensed Durham’s absence before reaching across the bed to confirm it, then she lay still for a while and listened. All she heard was distant coughing, coming from another flat. No lights were on; she would have seen the spill.

The smell hit her as she stepped out of the bedroom. Shit and vomit, with a sickly sweet edge. She had visions of Durham reacting badly to a day of stress and a night of champagne, and she almost turned around and went back to the bedroom, to open the window and bury her face in a pillow.

The bathroom door was half-closed, but there were no sound effects suggesting that he was still in there; not a moan. Her eyes began to water. She couldn’t quite believe that she’d slept through all the noise.

She called out, “Paul? Are you all right?” There was no reply. If he was lying unconscious in a pool of vomit, alcohol had nothing to do with it; he had to be seriously ill. Food poisoning? She pushed open the door and turned on the light.

He was in the shower recess. She backed out of the room quickly, but details kept registering long after she’d retreated. Coils of intestine. Bloodred shit. He looked like he’d been kneeling, and then sprawled sideways. At first, she was certain that she’d seen the knife, red against the white tiles—but then she wondered if in fact she’d seen nothing but the Rorschach blot of a random blood stain.

Maria’s legs started to give way. She made it to one of the chairs. She sat there, light-headed, fighting to remain conscious; she’d never fainted in her life, but for a time it was all she could do to keep herself from blacking out.

The first thing she felt clearly was a sense of astonishment at her own stupidity, as if she’d just marched, with her eyes wide open, straight into a brick wall. Durham had believed that his Copy had achieved immortality—and proved the dust hypothesis. The whole purpose of his own life had been fulfilled by the project’s completion. What had she expected him to do, after that? Carry on selling insurance?

It was Durham she’d heard screaming through gritted teeth, shaping her dream.

And it was Durham who’d kept pushing, Durham who looked like he’d tried to give birth.

She called for an ambulance. “He’s cut his abdomen open with a knife. The wound is very deep. I didn’t look closely, but I think he’s dead.” She found that she could speak calmly to the emergency services switchboard puppet; if she’d had to say the same things to a human being, she knew she would have fallen apart.

When she hung up, her teeth started chattering, and she kept emitting brief sounds of distress which didn’t seem to belong to her. She wanted to get dressed before the ambulance and police arrived, but she didn’t have the strength to move—and the thought of even caring if she was discovered naked began to seem petty beyond belief.