Permutation City

Zemansky said, 'They haven't accepted it yet. All they've said is that the first part of what we've told them makes no sense alone. They might ask about real-world physics, next.'

Durham closed his eyes, smiling. He said quietly, 'Let them ask. We'll explain everything -- right back to the Big Bang, if we have to.'

Repetto said, puzzled, 'I don't think it's holding.'

Durham glanced at the swarm. 'Give them a chance. They've barely tried it out.'

'You're right. But they're already sending back a . . . rebuttal.'

The swarm's new pattern was strong and simple: a sphere, rippling with waves like circles of latitude, running from pole to pole. Repetto said, 'The software can't interpret their response. I'm going to ask it to reassess all the old data; there may be a few cases where this dance has been observed before -- but too few to be treated as statistically significant.'

Maria said, 'Maybe we've made some kind of grammatical error. Screwed up the syntax, so they're laughing in our face -- without bothering to think about the message itself.'

Repetto said, 'Not exactly.' He frowned, like a man trying to visualize something tricky. Mouthpiece began to echo the spherical pattern. Maria felt a chill in her Elysian bowels.

Durham said sharply, 'What are you doing?'

'Just being polite. Just acknowledging their message.'

'Which is?'

'You may not want to hear it.'

'I can find out for myself, if I have to.' He took a step toward Repetto, more a gesture of impatience than a threat; a cloud of tiny blue gnat-like creatures flew up from the grass, chirping loudly.

Repetto glanced at Zemansky; something electric passed between them. Maria was confused -- they were, unmistakably, lovers; she'd never noticed before. But perhaps the signals had passed through other channels, before, hidden from her. Only now --

Repetto said, 'Their response is that the TVC rules are false -- because the system those rules describe would endure forever. They're rejecting everything we've told them, because it leads to what they think is an absurdity.'

Durham scowled. 'You're talking absurdities. They've had transfinite mathematics for thousands of years.'

'As a formality, a tool -- an intermediate step in certain calculations. None of their models lead to infinite results. Most teams would never go so far as to try to communicate a model which did; that's why this response is one we've rarely seen before.'

Durham was silent for a while, then he said firmly, 'We need time to decide how to handle this. We'll go back, study the history of the infinite in Lambertian culture, find a way around the problem, then return.'

Maria was distracted by something bright pulsing at the edge of her vision. She turned her head -- but whatever it was seemed to fly around her as fast as she tracked it. Then she realized it was the window on Elysium; she'd all but banished it from her attention, filling it in like a blind spot. She tried to focus on it, but had difficulty making sense of the image. She centered and enlarged it.

The golden towers of Permutation City were flowing past the apartment window. She cried out in astonishment, and put her hands up, trying to gesture to the others. The buildings weren't simply moving away; they were softening, melting, deforming. She fell to her knees, torn between a desire to return to her true body, to protect it -- and dread at what might happen if she did. She dug one hand into the Lambertian soil; it felt real, solid, trustworthy.

Durham grabbed her shoulder. 'We're going back. Stay calm. It's only a view -- we're not part of the City.'

She nodded and steeled herself, fighting every visceral instinct about the source of the danger, and the direction in which she should flee. The cloned apartment looked as solid as ever . . . and in any case, its demise could not, in itself, harm her. The body she had to defend was invisible: the model running at the far end of Durham's territory. She would be no safer pretending to be on Planet Lambert than she would pretending to be in the cloned apartment.

She returned.

The four of them stood by the window, speechless, as the City rapidly and silently . . . imploded. Buildings rushed by, abandoning their edges and details, converging on a central point. The outskirts followed, the fields and parks flowing in toward the golden sphere which was all that remained of the thousand towers. Rainforest passed in a viridian blur. Then the scene turned to blackness as the foothills crowded in, burying their viewpoint in a wall of rock.

Maria turned to Durham. 'The people who were in there . . . ?'

'They'll all have left. Shocked but unharmed. Nobody was in there -- in the software -- any more than we were.' He was shaken, but he seemed convinced.

'And what about the founders with adjoining territory?'

'I'll warn them. Everyone can come here, everyone can shift. We'll all be safe, here. The TVC grid is constantly growing; we can keep moving away, while we plan the next step.'

Zemansky said firmly, 'The TVC grid is decaying. The only way to be safe is to start again. Pack everything into a new Garden-of-Eden configuration, and launch Elysium again.'

Repetto said, 'If that's possible. If the infinite is still possible.' Born into a universe without limits, without death, he seemed transfixed by the Lambertians' verdict.

A red glow appeared in the distance; it looked like a giant sphere of luminous rubble. As Maria watched, it brightened, then broke apart into a pattern of lights, linked by fine silver threads. A neon labyrinth. A fairground at night, from the air. The colors were wrong, but the shape was unmistakable: it was a software map of the City. The only thing missing was the highway, the data link to the hub.

Before Maria could say a word, the pattern continued to rearrange itself. Dazzling pinpricks of light appeared within a seemingly random subset of the processes, then moved together, clustering into a tightly linked core. Around them, a dimmer shell formed by the remaining software settled into a symmetrical configuration. The system looked closed, self-contained.

They watched it recede, in silence.

31

Peer turned and looked behind him. Kate had stopped dead in the middle of the walkway. All the energy seemed to drain out of her; she put her face in her hands, then sank to her knees.

She said flatly, 'They've gone, haven't they? They must have discovered us . . . and now this is their punishment. They've left the City running . . . but they've deserted it.'

'We don't know that.'

She shook her head impatiently. 'They will have made another version -- purged of contamination -- for their own use. And we'll never see them again.' A trio of smartly dressed puppets approached, and walked straight through her, smiling and talking among themselves.

Peer walked over to her and sat cross-legged on the floor beside her. He'd already sent software probes hunting for any trace of the Elysians, without success -- but Kate had insisted on scouring a reconstruction of the City, on foot, as if their own eyes might magically reveal some sign of habitation that the software had missed.