Schild’s Ladder

The first part of the plan had succeeded: the core of the original femtomachine had been re-created, in miniature, in the far side. But it had not been as mobile as its designers had hoped, and Cass had been trapped by changing conditions, hundreds of times. She had kept struggling to get the Oppenheimer into position, proceeding in fits and starts, but the vehicle’s hull had become compromised, vendeks had flooded in.

If this had happened in the ferment of the Bright, Tchicaya doubted that any trace of the crippled machine would have remained a picosecond later, but the massed invasion by a single, tenacious species had effectively fossilized it whole. An unknown time later — near-side decades, or centuries — a group of intelligent xennobes had found the wreck. Subject to the same infestation themselves, they had revived the Oppenheimer with a vendek bred specifically to reverse the effects of the first.

Awake, but still trapped — nothing could remedy the fact that her vehicle was too primitive for the constantly evolving terrain — Cass had begun trying to communicate with her benefactors. Her own first message had taken the form of a layer population, vibrating, counting out the primes. From there, it had been a long, arduous process, but they’d eventually reached a point of limited mutual understanding.

Then the xennobes had vanished, prey to some shift in climate or culture; she had never discovered the reason. After decades had passed, another, related group had appeared, aware of the previous encounter, but speaking a different language themselves, and too impatient to learn to communicate properly. They had tried to carry her toward the border — knowing that this had been her original goal — without really understanding her nature. Moving anything through the far side was a delicate process, and their technology had not been up to the task. The Oppenheimer had become trapped again, damaged again. Invaded, frozen, and abandoned.

That was her last experience before waking on the deck of the Sarumpaet. She had no way of knowing whether the Oppenheimer had been towed here by the builders of the city, or whether the city had grown up around it.

Tchicaya was humbled; everything he’d been through was a stroll in the desert by comparison. He couldn’t even offer her the comfort of hearing that her own failed mission had been completed from the outside.

But he had to press on. As gently as he could, he began explaining what had happened on the near side. Cass had long ago faced up to the likelihood that her actions had destroyed whole worlds, but she’d had no way of knowing how much time had passed, and he could see the wounds reopening as he described the numbers, the scale of the evacuation.

He compressed the machinations of the factions on the Rindler to the briefest sketch, but he made one thing clear: the vast majority of people had never intended to destroy sentient life in the far side. Most still wanted the incursion to be halted, but not at the cost of genocide.

For all the bad news that accompanied it, understanding the Sarumpaet's presence seemed to solidify Cass’s sense of reality. She could connect herself to the near side again. She could imagine something other than exile, and madness.

When Tchicaya finished speaking, she stood. "You want them to evacuate the Bright, so you can trap the Planck worms there?"

"Yes."

"And you’d like me to translate that message?"

"If you can."

"I’ll need to be able to create vendeks," Cass explained. She had invented her own terminology for everything, but Tchicaya’s Mediator was smoothing over the differences. "I don’t understand the perceptual physiology, but there’s a family of short-lived vendeks related to the parasprites that my first xennobe tribe employed for communication. Though what their descendants will make of any of this, I don’t know."

Mariama worked with the toolkit to sort out interfaces with the software Cass had used back on the Oppenheimer to create the communications vendeks. While this was happening, Tchicaya rehearsed scenarios with her, possible responses from the Colonists. He wasn’t entirely sure why she wanted this, but she appeared to be afraid of being caught out, unprepared.

"Everything’s ready," Mariama declared. "As much as it will ever be."

They moved the Sarumpaet right up to the ruins of the Oppenheimer. The Colonists were still patiently looking on as the banner flashed out its mathematical lexicon.

Cass said, "I hope they really are expecting this. If I waved a papyrus at Tutankhamen and he started speaking to me, I’d probably run screaming from the room and never come back."

She sent the first vendeks out from the ship.

The scape painted a burst of color spreading out around them, fading rapidly as it moved. These vendeks did not last long in the room’s environment; to Tchicaya’s eyes, the signal looked faint by the time it reached the Colonists.