Pif started to say something, and he held up his hand.

She waited and chewed and drank.

“Can you,” he said, his voice no more than a whisper, “derive all the other forces from this equation? If we expand this to be multi-dimensional,” and he swallowed, “we can find out just how many dimensions reality has.”

She looked, and rubbed her eyes. “I… don’t know. I’m too tired to think straight anymore.”

Petrovitch shook his head. “Look, this is your baby. And your math is way better than mine. Go and get your head down: this will still be here when you get back.”

She groaned. “I don’t want to leave it. We’re so close.”

“It’ll be fine. I don’t want to come in here tomorrow and have to pry the finished proof out of your cold, dead hand. I’ll try and do some of the easy stuff—if I can manage that. That still leaves the really hard sums and most of the credit for you.”

“Don’t break the symmetry,” she warned.

“I thought I was supposed to.”

“Try without.”

“I’ll try with, then try without. And I’m going to use some real data, whether you like it or not.”

“Experimentalists. Have I told you how much I hate them?”

“Only about a thousand times.” Petrovitch shrugged. “Science: it works.”

Pif drank her coffee, and summoned enough strength to pick up her rucksack. “Are you sure about this?”

“Go,” he said. “See you in the morning. You can go through my shabby math while I cringe pathetically in a corner, then I can watch you reimagine the whole universe.”

She slung the rucksack over her shoulder. “If you put it like that, I don’t see how I can argue.”

“I might even get some of my own work done. You never know.”

“Boys and their toys,” she said, edging toward the door. “Sam, are you…?”

“Go away. There won’t be any sleep for a week if you crack this.”

She bowed her head, her beaded hair falling forward like a curtain. “Sam?”

“What?”

“I’m glad I’m sharing a room with you. You get me.”

“You mean you’re as dysfunctional as I am, just in different ways? Yeah, that’s about right. Now, in the name of whatever god you believe in, go.”

She nodded. She was halfway out into the corridor when she stopped. “What?” she said with typical directness.

“Police,” said a familiar voice.

“Chyort voz’mi!” He launched himself into his chair and folded his arms.

Pif put her head back around the door. “Sam? There’s a policeman here.”

“I know. Send him in, then go home. I’ll be fine.” He pushed his glasses up his face. “He’s not staying for longer than he absolutely needs to. Which is about a minute, if he’s lucky.”

Chain wandered in, blinking. “Petrovitch.”

“Detective Inspector Chain. Found my rat yet?”

“Ongoing inquiries,” he said. He glanced down at Pif’s desk and reached out to pick up one of her equations.

Petrovitch leaped up and slapped his hand down on top of the paper. “Touch nothing. Really.”

Chain held his hands up. “It didn’t look like it was going to break, but if you insist.” He looked around. “I was expecting big machines that sparked and hummed.”

“We keep those in the basement next to the reanimated bodies. What do you want?”

“Oh, I don’t know. How about five hundred thousand euros?”

“Back of the queue, Inspector. I have to be dead before you collect.”

“You think you’re smart?”

“I think I now stand a better chance of staying alive than I would relying on you. And thanks ever so much for sending Sorenson around. Not only did it get us both picked up by Marchenkho, I then had to get farmboy back to Oshicora before he realized his pet coder had gone awol.”

“You’re welcome,” said Chain. He opened a filing cabinet drawer and peered inside. “Interesting character, Sorenson. Did he give you his war hero spiel?”

“He might have mentioned something; it didn’t get him very far. Why?”

“That sort of stuff goes down really well in America, gets the folks onside. He tried it on me, so I thought I’d try and find out what he actually did for Uncle Sam.” He rolled the drawer shut. “It’s not pleasant reading. His civilian file is pretty thick, too. Not like your records—what little there is seems to fit together very neatly.”

“The truth has a habit of doing that.”

“So does something manufactured. You see, I can’t find any trace of a Samuil Petrovitch, aged twenty-two from St. Petersburg at all. Which could mean one of two things.”

Petrovitch pushed his glasses up his nose. “No, don’t tell me. I like games. I’m an Armageddonist with a suitcase bomb and head full of righteous fury, biding my time for, what, six years now before I set my nuke and kill you all. Or alternatively, Russian record keeping isn’t what its supposed to be. Your choice, I suppose.”

“Something’s not right, Petrovitch. I don’t like that. It makes me nervous, and when I get nervous, I get curious. Like a dog with a bone.”

“Your metaphors are all mixed, Inspector. You’d better watch out for that.” Petrovitch flexed his fingers, making his thumbs crack. “If that’s all, don’t let the door hit your zhopu on the way out.”

Chain harrumphed, then wandered to the door. He reamed at his eye, and coughed hard. When he was done, he leaned on the handle and turned back to Petrovitch.

“Is she a good kisser?”

“Ahueyet? You’ve been following me!” Petrovitch stood up and went nose to nose with the detective. “No. You followed Sorenson. No, that’s not all of it, either. You bugged Sorenson so you could follow him.”

“Calm down, Petrovitch.” Chain put his hands up between them.

“Do you know what Oshicora will do if they find a police tag on him?”

“Pretty much.”

“They’ll kill him.” Petrovitch was breathing hard.

“Careful of your heart. But of course, you’re getting a new one, so it won’t matter soon.” Chain stepped out of the way of the opening door. “I could deport Sorenson right now, but I’m increasingly interested in this VirtualJapan he’s working on. I’d lose all that.”

“And you wonder why people hate the police.”

“No,” said Chain, “I’m up to speed on that, too. Go carefully, Petrovitch.”

13

Petrovitch only had half his mind on his tensors. The other half was gnawing furiously at an entirely different problem.

After ten minutes, he gave up, threw his pen down in disgust and dug around in his jacket pocket. Sorenson’s card was white and shiny, with a little animated logo spinning around in one corner. It had the company phone number embossed across the front, along with the URL: the back was over-printed with Sorenson’s name and mobile number.

He tapped the card on the desk, considered putting it back, considered throwing it in the bin, considered trying to tear at its hard plastic edges until it broke. He tossed it to one side and looked at the equation he’d started.

“Raspizdyai kolhoznii,” he muttered. The card stared back at him.

But he couldn’t concentrate.

He wrenched open a drawer and unrolled a keyboard. His screen was under a pile of books he hadn’t quite got around to returning to the stacks: he dragged it out and propped it against the fading spines. Some of the pixels had failed due to the weight of paper, but he could see around them.

He tapped the rubbery keys to make sure he had a connection, then logged on to his own computer.

There was a touch pad somewhere. He moved some monographs, and it was hiding underneath. He nudged it closer to the keyboard and got the two talking.

If he’d had his rat, the whole operation would have been simplicity itself, but he hadn’t bought it to make his life easy. He’d bought it for his insurance policy, the one he’d have to cash in if his world came tumbling down around him.