"Try sueing Pravda in Moscow," Agnes suggested.

"Try sueing Der Spiegel in Hamburg, for that matter." George ambled back with his drink and a little coaster to protect the table. "No – but there are underground magazines all over Europe who'd use it, and you can't sue them because they just fade away like smoke and start up again as something else. But that isn't the real question. If Moscow can persuade the French that this might be published about the Brit they're negotiating with, then they wouldn't touch Tyler with a ten-foot gaffe. They've got voters to think of, as well."

"There is one other little danger." Agnes said quietly. "Publishing this letter would be firing off all your ammunition in one broadside, and Moscow doesn't work like that, not usually. If I were them, I'd use it to put the screws on Tyler. I'd whisper to him, first. So if the letter just might exist and Moscow just might have it, how do we know Tyler isn't already their joe?"

The idea hung over them, like a thunderstorm reluctant to break.

George slumped down, clenching his glass with both hands. "That does it. Luxembourg is off. It has to be."

Maxim waited for Agnes, but she was staring blindly at a picture over the fireplace, a very detailed view of a dead hare and several flowers. He said pleasantly: "You're surrendering rather quickly, aren't you?"

"Harry, in politics, it is better never to have loved at all than to have loved and lost."

"Then Moscow wins without firing a shot. Probably without even knowing they've won, since they most likely haven't got the letter, and won't understand why you've pulled out of the Luxembourg talks."

"You're in deep waters, Harry," Agnes said, without looking at him.

"I'll try and remember to hold my breath." Maxim went on watching George, his face expressionless and his eyes cold. "You're making sure the French would believe anything – anything – Moscow says about Tyler, whether they've got the letter or just dreamed something up on the spot. They could say he was gay and Paris would have to believe it, because we've dropped him from the first team."

Agnes opened her mouth, then shut it again. George grunted, staring at the backs of his hands and finding no encouragement there in the wrinkles and blotches. Some things were irreversible. Life was irreversible. He wished he were Maxim's age.

"Harry – I don't take these decisions-"

"You're giving the advice."

"It's for the Headmaster to decide."

"So what can we lose that we aren't throwing away now?"

"Harry, this is a matter of national defence."

"What in the hell do you think Army officers are for?"

"Show-jumping," Agnes said, and as Maxim snapped out of his chair she knew he was going to hit her and possibly kill her. Her training was no use against his training.

Then he stopped, just as abruptly as he'd started.

"I'm sorry, Harry," she mumbled breathlessly. "It was a bloody stupid thing to say. I'm sorry."

George gave a long, long sigh that ended as a groan. "You weren't called in to advise at these levels, Harry."

Maxim nodded, looking down at his shoes and blinking quickly. "Then as a voter and a taxpayer… You must know what Tyler's going to propose at Luxembourg, and he obviously won't go there alone. If Moscow's pulling his strings and he proposes something different, you'll know straight away. And as far as a scandal goes, you have to balance that against the value of an agreement with the French. I dare say it's a risk. But if you don't fight any battles, you won't win any wars."

"That doesn't sound much like the viewpoint of the average taxpayer." He looked up at Agnes. "Since it appears to be the open season, would Little Miss Muffet care to take a shot?"

She frowned and said slowly: "You always have to work with flawed material. There may still be a few saints around – I like to believe there are – but they don't go into politics or nuclear strategy."

For a long time, George turned the heavy cut-glass tumbler in his chubby hands. Then he said simply: "Those are honest points of view. I'll put them to the Headmaster along with whatever else I give him."

George often wondered what the PM would have decided. As it was, two days later, Moscow decided for him.

Professor John White Tyler hadn't slept in college that night. Even so, he would normally have been back in his rooms with plenty of time to make coffee, skim through the morning papers and perhaps hear the radio news headlines before his ten o'clock lecture. But the girl he had woken up with was doing a thesis on Hindu literature, and their farewell was a long and complicated act that Tyler thought he had once seen carved in full frontal colour on a Katmandu temple. He was delighted with a girl of such dedication, but it did mean that he only had time to change his shirt, find the file for that lecture, and hurry out again. He had shaved the evening before. He always did.

"The most carefully conceived and most believable nuclear targetting policy carries with it no guarantee that any government or leader will actually implement it at the moment of decision. You may build the most perfect rifle for hunting dangerous game, precisely fitted to your customer's arm length and the weight of trigger pull he prefers – but you cannot build in any device that will make him aim straight and squeeze the trigger at the moment the tiger charges."

He laid his hands flat on the side of the lectern and glanced up at the undergraduates stacked in front of him. There were more of them than usual, gazing blankly down from behind their curved stalls made of cheap wood the vivid orange colour of unfried fishcakes. Perhaps somebody else had been recommending this lecture to his own students.

"Nor should you be able to," he said clearly.

"At that point, the hunter has at least four options. He can stand there and be torn apart. He can shoot the tiger. He can fire wild to scare the tiger away – making it back down from a confrontation. Or he can back down himself, metaphorically, by climbing the nearest tree in somewhat of a hurry."

A ripple of laughter went through most of his audience, but not all. There was a pale, unamused group sitting slightly apart from the rest, with a few girls among it, which was odd for a military studies lecture.

"Only two of these four options owe anything to the gunsmith's art, and I think we might agree that it is not his job to decide whether the world would be a better place with or without the tiger concerned. He simply provides his customer with options. The customer decides which one to opt for. In terms of war, which has not yet been downgraded to the status of a sport, where the only objective is to win-"

"Fascist bastard," said one of the girls, but rather quickly and tentatively.

Tyler ignored her. "War remains what it has always been: a continuation of politics by other means. So every option has to be seen as a political one, no matter whether it is offered up by the military, the commercial world, or even the academics – taken together, the gunsmiths."

"Fascist bastard," the girl said again, with more conviction.

"Nazi," one of boys added.

"Could you make up your minds?" Tyler asked in a polite deep voice. "Either I was in an Italian nationalist movement started in the 1920's or in the National Socialist party in Germany led by Adolf Hitler. I don't think they allowed you to belong to both."

That got a sympathetic laugh from his usual audience. The girl muttered: "Sod you."

At the top of the central aisle, there were double swing doors with big glass port-holes in them – scuttles, as the Navy would call them, smugly confusing the landsman – and he had seen faces peeping quickly in. Usually that only happened at the end of the hour, when a new class was gathering for a different lecture.