Schild’s Ladder

“I came to the Rindler to give people a choice,” she said. “There are limits to the way that can be achieved, complications that I never anticipated, but working with the Colonists to find the solution would be an entirely honorable compromise.”

Tchicaya shook his head in mock admiration. “So you get to live exactly like a Yielder, while retaining your Preservationist credentials? Very slick.” He made it sound like a joke, but he was angry. He could forgive her the almost tongue-in-cheek self-serving spin. What he hated was the fact that she’d set her sights so far beyond his own, again.

He wasn’t ready to stay. He couldn’t live among the Colonists with her, when the arrival of every other near-sider was an eternity away. He’d planned to meet Rasmah on the other side of the border. He needed to see the stars at least one more time.

“You’ll go mad,” he said.

Mariama laughed. “That’s what my mother used to say, about travelers. Wandering from planet to planet, until they could no longer remember their own names.”

“Sounds romantic, doesn’t it? No wonder you couldn’t resist.” Tchicaya’s anger was fading, but the ache beneath it remained. He reached out and put his arms around her. There would never be an irrevocable parting, so long as they were both alive, but the gulf she was planning to create between them was the widest and the strangest he’d ever faced.

“What will I tell the version of you next to my kidney? She’ll think I made you walk the plank.”

“She’ll understand. I’ll give you a messenger for her.”

He pulled away, and held her at arm’s length. “What is it with you, that you always have to go further than anyone else?”

“What is it with you, that you always have to tag along?” Mariama ran her hand over his scalp, then she stood and walked to the doorway.

She stopped and turned back to face him. “Before I go, do you want to make love?”

Tchicaya was speechless. She had never once spoken of the possibility, since he’d willed an end to their first chance on Turaev.

“Now that I’m more your type,” she said, spreading her arms wide, as if showing off some enhancement to her appearance.

“More my type?” he replied stupidly. He couldn’t detect any change in her.

Mariama smiled. “Acorporeal.”

Tchicaya threw his pillow at her. She retreated, laughing.

He lay back on the bed, relieved. Nothing could have lived up to four thousand years of waiting. Except perhaps an original theorem.

Cass stood on the observation deck, listening patiently to Tchicaya’s appeal. Mariama had made herself scarce, and even the Colonists had finally noticed that their living legend began to emit incomprehensible streams of vendeks if they didn’t give her an occasional day off.

She’d done enough, he said. No sane person blamed her for her lack of omniscience. The Mimosans' plan to accelerate the far side had been ingenious, and she’d struggled valiantly to try to make it work, but the rules had changed, the prize she’d been reaching for had retreated into the distance. Other people could carry on in her place; the end result would be the same. And if she needed personal redemption, couldn’t that come from passing on her knowledge of the far side to someone rested, someone fully prepared for a second long haul?

Cass appeared calm, even slightly distracted. Tchicaya wondered if she’d taken in his words, if he should repeat himself from the beginning.

“I want to go swimming,” she said suddenly.

“Swimming?”

Cass nodded earnestly.

“All right.”

Tchicaya began to gesture at the scape, but she grabbed his arm. “In real water,” she insisted fiercely. “Real molecules of water.”

Tchicaya unclenched her grip on him, and held her by the shoulders. “Okay. As soon as we get out, you can do that.”

“I swim in real water; that’s who I am.” Her face contorted, and she emitted a long, anguished moan. “I didn’t want to be changed this much!”

“I’ll help you,” he promised. “I’ll get you out of here.”

On her last day in Museum City, Cass steered the Sarumpaet unescorted through the corridors and tunnels, searching for something. “I asked Hintikka, and she made some inspired guesses, but we never got around to investigating all the possibilities. The Colonists don’t really understand graphs, but they have a system for describing vendeks that maps quite well on to our picture, if you know how to make allowances for the parts that don’t match up.”

They veered from wall to wall, scrutinizing various living gadgets: lamps, air conditioners, fragrance dispensers, parasprite telephones, humor replenishers?—?Mariama’s name for the sacs full of endogenous vendeks that the Colonists imbibed to keep themselves in peak condition.

They probed the gadgets, and the toolkit did its best to infer the fine structure of the vendeks they contained. Tchicaya had no idea what Cass was hunting for. She had bidden farewell to the Colonists earlier, formally handing her diplomatic role on to Mariama. He didn’t know how well that notion translated, but Mariama had begun conversing with the xennobes for herself weeks before, and she seemed satisfied that her newcomer status would not be a handicap. Her own new ship had been prepared; she’d named it in honor of Tarek, in spite of the fact that he was still very much alive. But as she’d pointed out, there were only so many dead people.

“Not quite,” Cass muttered. She pulled the ship away from something whose most polite anthropomorphic equivalent was probably a spittoon.

Mariama glanced at Tchicaya inquiringly.

He said, “Don’t ask me. We’ll know when we find it.”

The tar pit had stabilized, and the toolkit’s models suggested that the Planck worms would have drowned in its depths. Other, grimmer scenarios could not be ruled out entirely, but as the Sarumpaet made its way back to the border it would seal the tar pit behind it; even if the ship was lost, they would not be opening up an easy channel for the Planck worms.

The worms would certainly have destroyed the interface across the border, but he and Cass would build their own, as close as possible to the old one; it shouldn’t be hard to catch the attention of the equipment on the Left Hand.

From there, they would transmit themselves to Pfaff. It was on the route to Earth, and Tchicaya would accompany her at least that much of the way.

Cass said, “Here it is.”

Tchicaya looked up at the toolkit’s display, a schematic of a graph, drawn node by node and edge by edge, superimposed over the larger scape portraying their busy surroundings.

It took him a moment to spot what she meant. Between two vendeks that resembled ornate ironwork, there was a plain, narrow, highly symmetrical layer.

It was the Diamond Graph. The state from which the whole near-side universe was believed to have arisen. Stable here, in this tiny sliver, cushioned between the right two vendeks.

The seed for a universe, lying in the gutter.

Cass gestured at the scape and summoned the image closer, placing it before them on the observation deck.

“That’s what I went looking for,” she said. “A glimpse of that. Only I never expected I’d come this close. And I never thought there’d be so much else attached.” She smiled uncertainly, then pushed the graph away.

“I think I’m ready to go home.”