Then the floor suddenly dropped beneath her like a hangman’s trapdoor, and she and the translator were dumped into a hold full of dangling spirals of cannisters.

“What did he say?” she demanded. “You got that wrong.” But the translator was staring up, shaking, still clinging to her. A shot rang out. Just one shot, but Dr. Rat had been almost nose to muzzle with the thug’s pistol, and a bullet meant to kill a human would tear a rat in half.

“Merciful God,” Khan whispered.

The two of them were still in the pool of light from above. She made to move, and then realized there were bodies all around her. She shrieked, seeing heavily laden rodents pressing in like diminutive zombies. And humans, too: Lee Pryor, of all bloody people, and that lanky white girl, her friend.

“Everyone get in close!” Pryor was shouting, and Kay felt a score of clutching hands scrabbling at her.

“What the fuck’s going on?” she said shrilly.

Mal grabbed Pryor’s arm and lunged for Kay’s shoulder.

“Boom,” she declared.

Nothing happened.

Pryor glanced from her to Khan. “I thought this was it. I thought we just had to touch.”

“Yeah.”

“Oh, this is all very nice, but you little turds all better come up here right now.” The thug was leaning through the hatch, upside down, gun levelled. Kay tried not to see the way he was spattered with blood. Oh God, oh merciful God, I don’t know if you care for poor, brave rat-creatures, but… The gun seemed to have a magnetic presence, drawing her gaze to its brutal lines.

“I’m going to count to three,” Rove’s man said.

Kay watched the translator, at her feet, take a lead from its implant and connect it to a socket in the floor. Perhaps it said something, because the other rats were clustering even closer to her, clinging to her clothes, her ankles, anything they could reach.

“Two,” said the thug.

For the second time the floor opened up beneath her. Only now there was no more airship beneath them, just the vastness of the sky and the bowl of an alien Earth.

Interlude: The Purists

Excerpt from Other Edens: Speculative Evolution and Intelligence by Professor Ruth Emerson of the University of California

Two and a half million years ago, give or take, and a familiar world. Perhaps a few more varieties of macrofauna, a surplus of shapes of elephant. But there are apes that look like our ancestors to be found across Africa, ready to make their great leap forwards to seize the reins of evolutionary destiny.

This branch leads to a world gone awry, ever so slightly. For many ages, it is another cold Earth. The delicate interactions of orbit and albedo, the tugs of near-miss asteroids, the fluctuations of the sun itself introduce a variability that plays out somewhat differently every time.