Permutation City

“How?”

“I don’t know. Go and stand in the middle…”

Durham looked dubious, but he limped forward and reached the doorway well ahead of her. He stepped right through, then turned and stood with one foot on either side, reaching out a hand to her, ready to drag her onto the departing train. She had a vision of him, bisected, one half flopping bloodily into each world.

She said, “I hope this… bastard was a great… philanthropist. He’d better… have been a fucking… saint.”

She looked to the side of the doorway. The corridor’s dead end was only centimeters away. Durham must have read the expression on her face; he retreated into the control room. The doorway touched the wall, then vanished. Maria bellowed with frustration, and dropped Riemann onto the carpet.

She ran to the wall and pounded on it, then sank to her knees. She was going to die here, inside a stranger’s imploding fantasy. She pressed her face against the cool paintwork. There was another Maria, back in the old world—and whatever else happened, at least she’d saved Francesco. If this insane dream ended, it ended.

Someone put a hand on her shoulder. She twisted around in shock, pulling a muscle in her neck. It was Durham.

“This way. We have to go around. Hurry.”

He picked up Riemann—he must have repaired his ankle in Elysium, and no doubt strengthened himself as well—and led Maria a short way back down the corridor, through a vast library, and into a storage room at the end. The doorway was there, a few meters from the far wall. Durham tried to walk through, holding Riemann head first.

Riemann’s head disappeared as it crossed the plane of the doorway. Durham cried out in shock and stepped back; the decapitation was reversed. Maria caught up with them as Durham turned around and tried backing through the doorway, dragging Riemann after him. Again, the portion of Riemann’s body which passed through seemed to vanish—and as his armpits, where Durham was supporting him, disappeared, the rest of him crashed to the floor. Maria ducked behind the doorway—and saw Riemann, whole, lying across the threshold.

They couldn’t save him. This world had let them come and go—on its own terms—but to Riemann himself, the exit they’d created was nothing, an empty frame of wood.

She went back and stepped over him, into Elysium. As the doorway retreated, Riemann’s shoulders came into view again. Durham, sobbing with frustration, reached through and dragged the sleeping man along for a meter—and then his invisible head must have struck the invisible wall, and he could be moved no further.

Durham withdrew into Elysium, just as the doorway became opaque. A second later, they saw the outside wall of the house. The implosion—or separation—accelerated as the doorway flew through the air above the grounds; and then the whole scene was encircled by darkness, like a model in a glass paperweight, floating off into deep space.

Maria watched the bubble of light recede, the shapes within melting and reforming into something new, too far away to decipher. Was Riemann dead, now? Or just beyond their reach?

She said, “I don’t understand—but whatever the Lambertians are doing to us, it’s not just random corruption… it’s not just destroying the TVC rules. That world was holding together. As if its own logic had taken precedence over Elysium’s. As if it no longer needed us.”

Durham said flatly, “I don’t believe that.” He crouched beside the doorway, weighed down by defeat.

Maria touched his shoulder. He shrugged free. He said, “You’d better hurry up and launch yourself. The other Elysians will have been removed from the seed, but everything else—all the infrastructure—should still be there. Use it.”

“Alone?”

“Make children, if you want to. It’s easy; the utility programs are all in the central library.”

“And—what? You’ll do the same?”

“No.” He looked up at her and said grimly, “I’ve had enough. Twenty-five lives. I thought I’d finally discovered solid ground—but now it’s all crumbling into illusions and contradictions. I’ll kill myself before the whole thing falls apart: die on my own terms, leaving nothing to be explained in another permutation.”

Maria didn’t know how to respond. She walked over to the interface window, to take stock of whatever was still functioning. After a while, she said, “The Autoverse spy software has stopped working—and the entire hub has gone dead—but there’s some last-minute summary data in the copy of the central library you made for the seed.” She hunted through Repetto’s analysis and translation systems.

Durham came and stood beside her; he pointed out a highlighted icon, a stylized image of a swarm of Lambertians.

He said, “Activate that.”

They read the analysis together. A team of Lambertians had found a set of field equations—nothing to do with the Autoverse cellular automaton—with thirty-two stable solutions. One for each of their atoms. And at high enough temperatures, the same equations predicted the spontaneous generation of matter—in exactly the right proportions to explain the primordial cloud.

The dance had been judged successful. The theory was gaining ground.

Maria was torn between resentment and pride. “Very clever—but how will they ever explain four humanoid robots abandoned in a meadow?”

Durham seemed bleakly amused. “They arrived in a spaceship, didn’t they? Aliens must have sent them, as emissaries. There must be other stars out there—concealed behind a suitable dust cloud.”

“Why should aliens try to tell the Lambertians about the TVC cellular automaton?”

“Maybe they believed in it. Maybe they discovered the Autoverse rules… but since they still couldn’t explain the origin of the elements, they decided to embed the whole thing in a larger system—another cellular automaton —complete with immortal beings to create the Autoverse, primordial cloud and all. But the Lambertians will put them straight: there’s no need for such a convoluted hypothesis.”

“And now the Autoverse is sloughing us off like dead skin.” Maria gazed at the Lambertian field equations; they were far more complex than the Autoverse rules, but they had a strange elegance all their own. She could never have invented them herself; she was sure of that.

She said, “It’s not just a matter of the Lambertians out-explaining us. The whole idea of a creator tears itself apart. A universe with conscious beings either finds itself in the dust… or it doesn’t. It either makes sense of itself on its own terms, as a self-contained whole… or not at all. There never can, and never will be, Gods.”

She displayed a map of Elysium. The dark stain marking processors which had ceased responding had spread out from the six public pyramids and swallowed most of the territories of Riemann, Callas, Shaw, Sanderson, Repetto and Tsukamoto. She zoomed in on the edge of the darkness; it was still growing.

She turned to Durham and pleaded, “Come with me!”

“No. What is there left for me to do? Descend into paranoia again? Wake up wondering if I’m really nothing but a discredited myth of Planet Lambert’s humanoid alien visitors?”

Maria said angrily, “You can keep me company. Keep me sane. After all you’ve done to me, you owe me that much.”

Durham was unmoved. “You don’t need me for that. You’ll find better ways.”

She turned back to the map, her mind going blank with panic for a moment—then she gestured at the growing void. “The TVC rules are dissolving, the Lambertians are destroying Elysium—but what’s controlling that process? There must be deeper rules, governing the clash of theories: deciding which explanations hold fast, and which dissolve. We can hunt for those rules. We can try to make sense of what went on here.”

Durham said sardonically, “Onward and upward? In search of higher order?”

Maria was close to despair. He was her one link to the old world; without him, her memories would lose all meaning.

“Please! We can argue this out in the new Elysium. But there’s no time now.”

He shook his head sadly. “Maria, I’m sorry—but I can’t follow you. I’m seven thousand years old. Everything