This was the problem that taxed Percival Godliman in the summer of 1940, when Hitler's armies swept across the French cornfields like a scythe and the British poured out of the Dunkirk bottleneck in bloody disarray. Professor Godliman knew more about the Middle Ages than any man alive. His book on the Black Death had upended every convention of medievalism; it had also been a bestseller and published as a Penguin Book. With that behind him he had turned to a slightly earlier and even more intractable period.

At 12:30 on a splendid June day in London, a secretary found Godliman hunched over an illuminated manuscript, laboriously translating its mediaeval Latin, making notes in his own even less legible handwriting. The secretary, who was planning to eat her luncheon the garden of Gordon Square, did not like the manuscript room because it smelled dead. You needed so many keys to get in there, it might as well have been a tomb.

Godliman stood at a lectern, perched on one leg like a bird, his face lit bleakly by a spotlight above-he might have been the ghost of the monk who wrote the book, standing a cold vigil over his precious chronicle. The girl cleared her throat and waited for him to notice her. She saw a short man in his fifties, with round shoulders and weak eyesight, wearing a tweed suit. She knew he could be perfectly sensible once you dragged him out of the Middle Ages. She coughed again and said, "Professor Godliman?"

He looked up, and when he saw her he smiled, and then he did not look like a ghost, more like someone's dotty father. "Hello!" he said, in an astonished tone, as if he had just met his next-door neighbour in the middle of the Sahara Desert.

"You asked me to remind you that you have lunch at the Savoy with Colonel Terry."

"Oh, yes." He took his watch out of his waistcoat pocked and peered at it. "If I'm going to walk it, I'd better leave now."

She nodded. "I brought your gas mask."

"You are thoughtful." He smiled again, and she decided he looked quite nice. He took the mask from her and said, "Do I need my coat?"

"You didn't wear one this morning. It's quite warm. Shall I lock up after you?"

"Thank you, thank you." He jammed his notebook into his jacket pocket and went out. The secretary looked around, shivered, and followed him.

Colonel Andrew Terry was a red-faced Scot, pauper-thin from a lifetime of heavy smoking, with sparse dark-blond hair thickly brilliantined. Godliman found him at a corner table in the Savoy Grill, wearing civilian clothes. There were three cigarette stubs in the ashtray. He stood up to shake hands.

Godliman said, "Morning, Uncle Andrew." Terry was his mother's baby brother.

"How are you, Percy?"

"I'm writing a book about the Plantagenets." Godliman sat down.

"Are your manuscripts still in London? I'm surprised."

"Why?"

Terry lit another cigarette. "Move them to the country in case of bombing."

"Should I?"

"Half the National Gallery has been shoved into a bloody big hole in the ground somewhere up in Wales. Young Kenneth Clark is quicker off the mark than you. Might be sensible to take yourself off out of it too, while you're about it. I don't suppose you've many students left."

"That's true." Godliman took a menu from a waiter and said, "I don't want a drink."

Terry did not look at his menu. "Seriously, Percy, why are you still in town?"

Godliman's eyes seemed to clear, like the image on a screen when the projector is focused, as if he had to think for the first time since he walked in. "It's all right for children to leave, and national institutions like Bertrand Russell. But for me, well, it's a bit like running away and letting other people fight for you. I realise that's not a strictly logical argument. It's a matter of sentiment, not logic."

Terry smiled the smile of one whose expectations have been fulfilled. But he dropped the subject and looked at the menu. After a moment he said, "Good God. _Le Lord Wool Pie_."

Godliman grinned. "I'm sure it's still just potatoes and vegetables."

When they had ordered, Terry said, "What do you think of our new Prime Minister?"

"The man's an ass. But then, Hitler's a fool, and look how well he's doing. You?"

"We can live with Winston. At least he's bellicose."

Godliman raised his eyebrows. "'We?' Are you back in the game?"

"l never really left it, you know."

"But you said-"

"Percy. Can't you think of a department whose staff all say they don't work for the Army?"

"Well, I'm dammed. All this time…"

Their first course came, and they started a bottle of white Bordeaux. Godliman ate potted salmon and looked pensive. Eventually Terry said, "Thinking about the last lot?"

Godliman nodded. "Young days, you know. Terrible time." But his tone was almost wistful.

"This war isn't the same at all. My chaps don't go behind enemy lines and count bivouacs like you did. Well, they do, but that side of the thing is much less important this time. Nowadays we just listen to the wireless."

"Don't they broadcast in code?"

Terry shrugged. "Codes can be broken. Candidly, we get to know just about everything we need these days."

Godliman glanced around, but there was no one within earshot, and it was hardly for him to tell Terry that careless talk costs lives.

Terry went on, "In fact my job is to make sure they don't have the information they need about us."

They both had chicken pie to follow. There was no beef on the menu. Godliman fell silent, but Terry talked on.

"Canaris is a funny chap, you know. Admiral Wilhelm Canaris, head of the Abwehr. I met him before this lot started. Likes England. My guess is he's none too fond of Hitler. Anyway, we know he's been told to mount a major intelligence operation against us, in preparation for the invasion, but he's not doing much. We arrested their best man in England the day after war broke out. He's in Wandsworth prison now. Useless people, Canaris' spies. Old ladies in boarding-houses, mad Fascists, petty criminals."

Godliman said, "Look here, old boy, this is too much." He trembled slightly with a mixture of anger and incomprehension. "All this stuff is secret. I don't want to know!"

Terry was unperturbed. "Would you like something else?" he offered. "I'm having chocolate ice cream."

Godliman stood up. "I don't think so. I'm going to go back to my work, if you don't mind."

Terry looked up at him coolly. "The world can wait for your reappraisal of the Plantagenets, Percy. There's a war on, dear boy. I want you to work for me."

Godliman stared down at him for a long moment. "What on earth would I do?"

Terry smiled wolfishly. "Catch spies."

Walking back to the college, Godliman felt depressed despite the weather. He would accept Colonel Terry's offer, no doubt about that. His country was at war; it was a just war; and if he was too old to fight, he was still young enough to help.

But the thought of leaving his work-and for how many years?-depressed him. He loved history and he had been totally absorbed in mediaeval England since the death of his wife ten years ago. He liked the unravelling of mysteries, the discovery of faint clues, the resolution of contradictions, the unmasking of lies and propaganda and myth. His new book would be the best on its subject written in the last hundred years, and there would not be one to equal it for another century. It had ruled his life for so long that the thought of abandoning it was almost unreal, as difficult to digest as the discovery that one is an orphan and no relation at all to the people one has always called Mother and Father.

An air raid warning stridently interrupted his thoughb. He contemplated ignoring it-so many people did now-and he was only two minutes' walk from the college. But he had no real reason to return to his study; he knew he would do no more work today. So he hurried into a tube station and joined the solid mass of Londoners crowding down the staircases and on to the grimy platform. He stood close to the wall, staring at a Bovril poster, and thought, But it's not just the things I'm leaving behind. Going back into the game depressed him, too. There were some things he liked about it: the importance of little things, the value of simply being clever, the meticulousness, the guesswork. But he hated the blackmail, the deceit, the desperation, and the way one always stabbed the enemy in the back.