Alison was well aware that her hierarchy of needs was some way off Maslow’s, and at the top of it was information. She angled for Khan’s eye until the scientist wandered over.

“Listen,” she hissed, “I don’t know who these people are, or what they’ve offered you, but they are not your friends.” She was aware that everyone there could doubtless hear every word. It was ridiculous, but she persisted. “They’re enemies of the state.”

Khan sat on the arm of the sofa and brought out a half-empty pack of cigarettes. “Oh, love, I don’t think they care about ‘the state.’ ” She made a joke of it, but there was a hollowness to her manner, a fragility that spoke of having seen too many things.

“Doctor—Kay, please. They’re dangerous people, you don’t know—”

“I’ve seen them kill someone already,” Khan said with almost desperate cheer. “Or at least punch the bastard hard enough to do the job. And they did for Billy White and his friends. Would it help to say they’ve only brutally murdered people in my defence? People and…things.”

“Kay, my name is Alison Matchell. I’m a colleague of Julian Sabreur. He’s trying to find you. If you get the chance, call him. He’ll keep you safe.” Khan had lit up by then—and Alison couldn’t fight an instinctive flinch as the woman turned her head and exhaled a plume of smoke.

Khan saw it. “Don’t worry, love,” she said, deadpan. “Most likely none of us’ll live long enough to regret it.”

“So much for their assurances that I’ll be safe,” Alison said, trying to match her bantering tone.

“Oh, not them. It’s just the universe is going to end. And I’d like to laugh that off but they showed me a proof. Elegant, it was, working from first principles. Must have given them a real headache to put it into a notation I’m familiar with, but they did a good job. Whole universe, falling in on itself like a broken ice sculpture.” Her non-smoking hand made a crushing gesture to demonstrate.

“That’s mad,” Alison said flatly.

“We’re all mad here,” Khan rejoined archly. “Your life has been eminently sane recently, has it?”

Alison opened her mouth, thinking, Carried across a red rock ruin, through the wall of my kitchenette; touching some frozen bloody invisible supercomputer with my mind, and shut it again.