"They've got a scarcity economy all right," says Pierre. "Bandwidth is the limited resource, that and matter. This whole civilization is tied together locally because if you move too far away, well, it takes ages to catch up on the gossip. Matrioshka brain intelligences are much more likely to stay at home than anybody realized, even though they chat on the phone a lot. And they use things that come from other cognitive universes as, well, currency. We came in through the coin slot, is it any wonder we ended up in the bank?"

"That's so deeply wrong that I don't know where to begin," Amber grumbles. "How did they get into this mess?"

"Don't ask me." Pierre shrugs. "I have the distinct feeling that anyone or anything we meet in this place won't have any more of a clue than we do – whoever or whatever built this brain, there ain't nobody home anymore except the self-propelled corporations and hitchhikers like the Wunch. We're in the dark, just like they were."

"Huh. You mean they built something like this, then they went extinct? That sounds so dumb …"

Su Ang sighs. "They got too big and complex to go traveling once they built themselves a bigger house to live in. Extinction tends to be what happens to overspecialized organisms that are stuck in one environmental niche for too long. If you posit a singularity, then maximization of local computing resources – like this – as the usual end state for tool users, is it any wonder none of them ever came calling on us?"

Amber focuses on the table in front of her, rests the heel of her palm on the cool metal, and tries to remember how to fork a second copy of her state vector. A moment later, her ghost obligingly fucks with the physics model of the table. Iron gives way like rubber beneath her fingertips, a pleasant elasticity. "Okay, we have some control over the universe, at least that's something to work with. Have any of you tried any self-modification?"

"That's dangerous," Pierre says emphatically. "The more of us the better before we start doing that stuff. And we need some firewalling of our own."

"How deep does reality go, here?" asks Sadeq. It's almost the first question he's asked of his own volition, and Amber takes it as a positive sign that he's finally coming out of his shell.

"Oh, the Planck length is about a hundredth of a millimeter in this world. Too small to see, comfortably large for the simulation engines to handle. Not like real space-time."

"Well, then." Sadeq pauses. "They can zoom their reality if they need to?"

"Yeah, fractals work in here." Pierre nods. "I didn't —"

"This place is a trap," Su Ang says emphatically.

"No it isn't," Pierre replies, nettled.

"What do you mean, a trap?" asks Amber.

"We've been here a while," says Ang. She glances at Aineko, who sprawls on the flagstones, snoozing or whatever it is that weakly superhuman AIs do when they're emulating a sleeping cat. "After your cat broke us out of bondage, we had a look around. There are things out there that —" She shivers. "Humans can't survive in most of the simulation spaces here. Universes with physics models that don't support our kind of neural computing. You could migrate there, but you'd need to be ported to a whole new type of logic – by the time you did that, would you still be you? Still, there are enough entities roughly as complex as we are to prove that the builders aren't here anymore. Just lesser sapients, rooting through the wreckage. Worms and parasites squirming through the body after nightfall on the battlefield."

"I ran into the Wunch," Donna volunteers helpfully. "The first couple of times they ate my ghost, but eventually I figured out how to talk to them."

"And there's other aliens, too," Su Ang adds gloomily. "Just nobody you'd want to meet on a dark night."

"So there's no hope of making contact," Amber summarizes. "At least, not with anything transcendent and well-intentioned toward visiting humans."

"That's probably right," Pierre concedes. He doesn't sound happy about it.

"So we're stuck in a pocket universe with limited bandwidth to home and a bunch of crazy slum dwellers who've moved into the abandoned and decaying mansion and want to use us for currency. 'Jesus saves, and redeems souls for valuable gifts.' Yeah?"

"Yeah." Su Ang looks depressed.

"Well." Amber glances at Sadeq speculatively. Sadeq is staring into the distance, at the crazy infinite sunspot that limns the square with shadows. "Hey, god-man. Got a question for you."

"Yes?" Sadeq looks at her, a slightly dazed expression on his face. "I'm sorry, I am just feeling the jaws of a larger trap around my throat —"

"Don't be." Amber grins, and it is not a pleasant expression. "Have you ever been to Brooklyn?"

"No, why —"

"Because you're going to help me sell these lying bastards a bridge. Okay? And when we've sold it we're going to use the money to pay the purchasing fools to drive us across, so we can go home. Listen, this is what I'm planning …"

"I can do this, I think," Sadeq says, moodily examining the Klein bottle on the table. The bottle is half-empty, its fluid contents invisible around the corner of the fourth-dimensional store. "I spent long enough alone in there to —" He shivers.

"I don't want you damaging yourself," Amber says, calmly enough, because she has an ominous feeling that their survival in this place has an expiry date attached.

"Oh, never fear." Sadeq grins lopsidedly. "One pocket hell is much like another."

"Do you understand why —"

"Yes, yes," he says dismissively. "We can't send copies of ourselves into it, that would be an abomination. It needs to be unpopulated, yes?"

"Well, the idea is to get us home, not leave thousands of copies of ourselves trapped in a pocket universe here. Isn't that it?" Su Ang asks hesitantly. She's looking distracted, most of her attention focused on absorbing the experiences of a dozen ghosts she's spun off to attend to perimeter security.

"Who are we selling this to?" asks Sadeq. "If you want me to make it attractive —"

"It doesn't need to be a complete replica of the Earth. It just has to be a convincing advertisement for a presingularity civilization full of humans. You've got two-and-seventy zombies to dissect for their brains; bolt together a bunch of variables you can apply to them, and you can permutate them to look a bit more varied."

Amber turns her attention to the snoozing cat. "Hey, furball. How long have we been here really, in real time? Can you grab Sadeq some more resources for his personal paradise garden?"

Aineko stretches and yawns, totally feline, then looks up at Amber with narrowed eyes and raised tail. "'Bout eighteen minutes, wall-clock time." The cat stretches again and sits, front paws drawn together primly, tail curled around them. "The ghosts are pushing, you know? I don't think I can sustain this for too much longer. They're not good at hacking people, but I think it won't be too long before they instantiate a new copy of you, one that'll be predisposed to their side."

"I don't get why they didn't assimilate you along with the rest of us."

"Blame your mother again – she's the one who kept updating the digital rights management code on my personality. 'Illegal consciousness is copyright theft' sucks until an alien tries to rewire your hindbrain with a debugger; then it's a lifesaver." Aineko glances down and begins washing one paw. "I can give your mullah-man about six days, subjective time. After that, all bets are off."

"I will take it, then." Sadeq stands. "Thank you." He smiles at the cat, a smile that fades to translucency, hanging in the simulated air like an echo as the priest returns to his tower – this time with a blueprint and a plan in mind.

"That leaves just us." Su Ang glances at Pierre, back to Amber. "Who are you going to sell this crazy scheme to?"