"Like it?" Ivanov's eyes sparkled. "Colonel, five years ago, the GRU sent me there supposedly as a student on a six-months total immersion course in English for foreigners. It was a pure pleasure. I'd be happy to return."

"Well, let's get started," Lermov said.

The Astoria was acceptable, far better than most army accommodation. There were individual bedrooms with showers that worked, dull but functional. What had been the restaurant was more like a canteen now and run by the military, and the food was simple and sustaining, as you would expect it to be. In Lermov's case, he had an excellent goulash with a glass of a rough red wine to wash it down. He sat there, thinking about things over a second glass, and Ivanov appeared.

"Did you want lunch?" Lermov asked.

"I grabbed a couple of sandwiches and went up to headquarters. I've booked us an office for privacy-the main records department is about the size of a cathedral and just as public. Every file there ever was, lines of computers, poor sods in uniform hunched over. It looks like some Stalinist movie."

"God forbid," Lermov said, and stood up. "Let's get going and see what we can do."

Ivanov had been right about the central research hall, but it was surprisingly quiet-disciplined, really-the occasional voice in the distance, a constant low hum from the machines. The office was fine, two desks, each with a computer.

"Most of the data obviously is on computer these days," Ivanov said. "Even the old stuff has been transferred, but we can explore original documents if we want, it's still stored elsewhere. Now, where do we start?"

"I'm interested by the speed at which events moved. Kurbsky arrives in London, he's received at Holland Park, and then he's out on the street, walking round and speaking to Bounine. Twenty-four hours after that, he's in Mayfair and shooting some Chechnyan named Basayev with whom he's apparently had history. He calls Bounine afterwards, tells him what he's done, and says he's returning to Holland Park. Bounine tells Luzhkov and Luzhkov tells Putin. And then Kurbsky vanishes, and, two days later, so do Luzhkov and Bounine." Lermov stood, concentrating. "You have a look at all the traffic to and from the London Embassy, starting with the Thursday Kurbsky was received and the few days after. Transcripts of every kind. If a conversation looks odd or interesting, listen to the recording."

"And you?"

"I'm going to find out more about Kurbsky."

He switched on his computer and went quickly through Kurbsky's life. In January 1989, Kurbsky, aged nineteen, had been staying in London with his aunt Svetlana, a famous Russian actress and defector, when news came of student riots in Moscow, blood on the streets and many dead, amongst them his sister, Tania Kurbsky. Their father, a KGB colonel, had used his influence to have her buried in Minsky Park military cemetery to cover his shame. Apparently too late for her funeral, Alexander Kurbsky's response had been to join the paratroopers in the ranks and go to Afghanistan and then Chechnya, and then Iraq. He'd excelled. Then, Boris Luzhkov had recruited him for his mission to penetrate British intelligence. His bait? That Tania Kurbsky wasn't dead at all but sentenced to life in the worst gulag in Siberia, Station Gorky. If Kurbsky cooperated, his sister would go free.

He sat thinking about it, and then, using GRU operational passwords, accessed prisoners' lists and files at Station Gorky. When he tapped in the name of Tania Kurbsky, however, the screen said Code 9 Restriction. He turned to Ivanov, busy at his own computer, and asked, "What's a Code 9 Restriction?"

"Ah, you've got to Tania Kurbsky. I ran into the same roadblock. It means above most secret, which, when I inquired of Major Levin out there in the end office, means you can't have it, whoever you are and whatever it is."

"We'll see about that. Let's go and have a word."

Major Levin was impressed enough when faced with a full colonel of GRU to get to his feet. "Can I assist in any way, Colonel…?"

"Lermov. I'm engaged in an essential intelligence matter, and my inquiry is blocked by the words Code 9 Restriction."

"I'm afraid it would be impossible to help you, Colonel."

Lermov took the envelope from his pocket, extracted Putin's letter, and passed it across. Levin read it, eyes bulging.

"Of course, you could phone through to the Prime Minister's Office in the Kremlin or you could simply unlock the information. Right here on your own screen would do."

"Of course, sir, I'm most happy to oblige. If you would be kind enough to show me what it is you seek, I can insert the correct password."

"Excellent." Lermov turned to Ivanov. "You will oblige me, Captain? I wouldn't look if I were you, Major."

Ivanov's fingers flew expertly, the prisoners' lists at Station Gorky appeared with Tania Kurbsky's name, again blocked. Major Levin scribbled a password and passed it over, and Ivanov tapped it in. The screen was filled with the sad, haunted face of a wretched woman looking about a hundred years old. It read: "Tania Kurbsky died of typhoid, aged 28, on March 7, 2000."

"Have you got what you wanted, gentlemen?" Levin inquired.

"Yes, I think so."

He got up, and Levin said, "Is there anything else I can do?"

"Yes, make sure you forget about this. It would seriously displease the Prime Minister if he heard you'd been uncooperative at first."

They returned to the office, and Ivanov said, "I don't think I'll forget that face in a hurry. She was only seventeen when she went in. That means she endured that place for eleven years."

"I agree. So Luzhkov was lying when he said she was still alive."

"Do you think the Prime Minister knew?"

"I'd like to think he didn't, but who knows? The real question is this: what would Alexander Kurbsky do if he found out? The fact that his old bastard of a father had lied when he said she was dead in the first place must have deeply shocked him, but to discover the awful truth about his sister and realize how cruelly he had been duped…" He shook his head. "I don't think angry would be strong enough to describe how he would feel. And how he would react is anyone's guess."

"Do you think that perhaps he did find out?" Ivanov asked.

"That's what we need to discover. Did you come across anything else?"

"Just one thing. You remember the Big Four meeting the other month?"

"Of course." The American Vice President had unexpectedly flown in from Paris for top secret talks with the Prime Minister, the Israeli Prime Minister, and the President of Palestine to broker a deal on Gaza.

"You remember they met on a large boat on the Thames? Well, according to some reports, it got a little dangerous out there in the mist. Some small riverboat exploded, an overheated gas tank or something."

"And the point?"

"It was the last day anyone at the Embassy saw either Luzhkov or Bounine."

"Interesting," Lermov said. "You think it was related?"

"You said to look for anything odd," said Ivanov. "And here's another thing. Apparently, Luzhkov knew the Vice President was flying in. I found a message about it from the Paris Embassy at approximately midnight on the night before. It was received by a junior lieutenant named Greta Bikov-and signed for by Boris Luzhkov."

"Hmm. That doesn't really tell us anything, though. Tell me, who's been holding the fort for GRU in London since the disappearances?"

"A Major Ivan Chelek. They sent him over from Paris."

"I know him, he worked for me in Iraq some years ago. Slow but sound. You speak to him, explain you're acting under my orders. Find out what he's been doing to investigate, and inquire about Greta Bikov."

"Any special reason?" Ivanov asked.