“Rifle?”

“Yeah.” He clicked his torch off and let the red light behind his eyes be his guide. “You’re probably wondering how we got that through customs.”

“Her coat, though. We’ve got that. And boots and—”

“Tourist gear,” said Petrovitch. “I ordered her the same sort of stuff we’re wearing. It’s missing, so I assume she’s still got it all.”

“You knew. You knew all along. Why didn’t you tell me?”

“Because you’d have told Buchannan, and he’d have told Ben and Jerry.”

“You didn’t trust me with the information.”

“I still don’t. Get over it. I’m going to see the physics hut. You can poke about here, see if there’s anything left.”

There was no path as such – probably one would emerge once the snow had melted – but Petrovitch could see the squat shape in the distance, lit from above by a tenuous apple-green curtain that swung lazily in the sky.

It would have been a good night for an experiment. Lucy would be crouching down over her instruments, watching the real-time data stream across the screen, and she’d read the peaks and troughs like a composer looking at a stave and hearing the music. She’d have a cup of builder’s tea in her hands, and she’d reach forward to a panel every so often, to change the amplification of a signal or correct a drift in the driving voltage.

When he tore the police tape away and opened the door, she wasn’t there.

Her equipment was, though. Hand-crafted labels in her tiny, spidery handwriting identified each switch and knob. Inside the grey cases, her signature soldering would be plain.

A bare cable was draped over the desk. The computer it had been attached to had gone. That was something that was in the inventory of things taken to Seattle, yet Petrovitch knew it had never arrived.

He settled into the wheeled chair and turned on his torch.

She would have sat right there, rolling from place to place rather than getting up and walking the two steps to where she needed to be. Just like a kid.

“Michael?”

[Sasha.]

“Talk to me. Tell me something I want to hear.”

[You were right.]

“Good. I was beginning to think I was losing my touch.” He shone his torch at the clocks on the wall: old-school analogue clocks, each face as big as a dinner plate. Four of them, each marked with a plaque: GMT, Alaska Time, Pacific Time, Local Time. The last one read twenty-three minutes and a few seconds past twelve.

[We have made a further analysis of the electrical and electronic disruption experienced in the Deadhorse area. While all the events are essentially simultaneous, within a margin of error, it appears that by ignoring the error and relying on the raw timings alone, a pattern emerges from the data.]

Petrovitch leaned back. “Let me guess. Things get fried earlier in the east than the west.”

[It is a matter of tenths of seconds for some of the intervals. And the main explosion that registers on the seismographs destroys less sensitive electronics back up the range, confusing the data.]

“This is insane.”

[The obvious conclusion is—]

“It’s not obvious at all,” he complained. “But it’s the only conclusion left. Svolochi. Someone beat me to it.”

[Just because we can explain the phenomenon does not mean we can then know everything about it.]

“We need to. Someone put a fusion reactor in space. The Americans shot it down.”

[The Chinese have denied it was theirs.]

“So they say.” He got up and started to pace the tiny room. “I’m still up on fusion. I know people in all the top facilities. How the huy could this have gone under the wire, and then ended up in yebani orbit? We’re talking tonnes. Tens, probably hundreds of tonnes of wire, shielding, all sorts of crap.”

[Yet analysis of Vice Premier Zhao’s conversation with you did not reveal any unusual stress patterns. It is likely that he was telling you the truth. Is it possible that he is not party to this secret?]

“What’s not possible is that the Americans knew and we didn’t. But it has to be the Chinese.” He threw himself back into the chair. “Doesn’t it?”

[Their major facility is at Zhejiang. Analysis of their research yields no evidence of a single instance of a sustained fusion reaction.]

“Of course it doesn’t. I’d know about it, along with the rest of the planet.”

[And if they are not ready to reveal their success?]

“There’s a world of difference between everybody knowing you’ve done it but you’re denying it, and so secret that no one knows you’re even capable of it. I mean, fusion. Yobany stos.”

[And sitting here, in this room, Lucy Petrovitch worked it out.]

They were both silent, man and machine.

“Why did she run?”

[I do not know.]

Petrovitch slammed his fist on the desk. It was his right hand. If he’d used his left, he’d have reduced the thing to matchwood. “Every time. Every time it looks like we’re getting close, we find we’re really moving further away.”

[And now Joseph Newcomen is wondering what is delaying you.]

“Bring him down here. I want a second pair of eyes.”

He met the American at the door of the hut. Newcomen’s torch caused the snow to glow.

“Turn it off. I want to try something.”

“Will it involve you putting a gun to my head again?”

“No. I haven’t got an audience out here, and I don’t do it for my own personal pleasure anyway.”

Newcomen laboured at the switch until it clicked. Once again it was just the ground and the sky. The aurora flowed overhead, obscuring the stars as it washed across them.

“We have to think like her,” said Petrovitch. “Do you think you can do that?”

“I can try,” said Newcomen, even though his whole body seemed repelled at the idea of imagining himself a twenty-something foreign-born woman. “I don’t know how good I’ll be at it.”

“You’re sitting in that hut. No windows, no indication of what’s going on outside except what’s on your instruments. Then quickly, without warning, your readings go off the scale. Almost before you can react, everything dies. The lights go off, your computer stops, the screen goes blank. Most importantly, your link dies.” Petrovitch knew what that would do to him. For Lucy it was less immediately catastrophic, but all the same, it would have been a surprising and bewildering experience. “What would you do?”

“The power’s gone. I’d find a torch.”

“Yeah, maybe. You try it, and you get nothing. Candle? Storm lantern?” He couldn’t remember seeing one, but he was forgetting something. “The next moment it sounds like God’s knocking to come in.”

“Then I go for the door. I open it and step outside.”

“It’s not dark any more. There’s a fireball, up in the sky, towards the west. You watch it boil away. The light fades and you’re left in the dark again.” Petrovitch stared at the horizon. Deadhorse was invisible. “Why? Why spend time putting things in a rucksack and then leaving the obvious place of safety?”

“Did she think she was under attack? That a war had started?” Newcomen spun slowly around. “How would she know which way to go?”

“She knew the night sky like the back of her hand. With or without a compass, she’d be able to navigate just fine.” Petrovitch grunted with frustration. “I thought coming here would make all the difference: that by seeing what she’d seen, I’d get some clue about where she’s gone.”

“And it hasn’t?”

“No.” He blew out the stale air from his lungs. “Let’s close up here for now. Go and get some food and some rest. Start early tomorrow and see where that gets us.”

Petrovitch turned his own torch on and trudged back to the main cluster of buildings, and the plane parked behind it.

“Did you find anything in the dormitory?” he asked Newcomen.

“Nothing. Stripped clean. They’ve taken the mattress she slept on. I… didn’t expect that.” He kicked at the snow. “It wasn’t part of our investigation.”