professor yoshiyama was little more than five feet in height and wore a judo jacket and trousers many times washed, a black belt around his waist. The face was the man’s most outstanding feature, the skin the colour of parchment and almost transparent. There was nothing weak there. Only strength and intelligence and a kind of gentleness. It could have been that of a saint or scholar. It was, in fact, the face of a great master who had practised his art for more than fifty years.

His voice was dry and rather pedantic, the vowels clipped slightly, but the dozen men sitting cross-legged on the floor were giving him all their attention. High in the balcony of the gymnasium, Mallory leaned on the rail and watched.

“The literal meaning of the two Japanese characters which make up the word karate is empty hands,” Yoshiyama said. “This refers to the fact that karate developed as a system of self-defence relying solely on unarmed techniques. The system was first developed centuries ago on the island of Okinawa during a time when the inhabitants were forbidden to carry arms on pain of death.”

There was a strangely old-fashioned flavour to everything he said, as if he were repeating a lesson painfully learned. He turned to a large wall chart which carried an outline of a human figure with all vital points, and their respective striking areas, clearly marked.

“The system consists of techniques of blocking or deflecting an attack and of counter-attacking by punching, striking or kicking.” He turned, his face bland, expressionless. “But there is more to karate that well-practised tricks and physical force.” He tapped his head. “There is also the mental application. You will be taught how to focus all your strength and energy on a single target at any given time. Let me show you what I mean.”

He nodded briefly and his two assistants picked up three lengths of planking. They were perhaps two feet long, each plank an inch thick. The two men took up their positions in front of Yoshiyama, holding the three planks between them and slightly above waist-level. In a single incredibly fluid motion the old man’s left foot stamped forward and his right fist moved up from the waist, knuckles extended. There was a report like a gunshot and the planks split from end to end.

A quick murmur rose from the class and Yoshiyama turned, quite unperturbed. “It is also possible to snap a brick in half with the edge of the hand.” He permitted himself one brief smile. “But this requires practice. Major Adams, please.”

A small, wiry, middle-aged man with greying hair and a black patch over his right eye stood up at the back of the class and came forward. Like Yoshiyama, he wore a black belt, but where his left arm should have been a metal limb dangled.

“You will observe that Major Adams is rather a small man," Yoshiyama said. “He is also no longer in the prime of life. If we add to this the fact that he has only one arm one would not under normal circumstances give him much hope of surviving any kind of physical assault. As it happens, however, his circumstances are far from normal.”

He nodded to one of his assistants and moved out of the way. The assistant, a young, powerfully built Japanese with dark hair, ran to the far side of the gymnasium. He selected a knife from a table which contained an assortment of weapons, turned and ran forward, a blood-curdling cry surging from his throat.

He swerved to one side, came to a dead stop, then moved in quickly, the knife slashing at the Major’s face. Adams moved with incredible speed, warding off the attacking arm with an extended knife-hand block. At the same moment he fell diagonally forward to one side and delivered a roundhouse kick to the groin. In what was virtually the same motion he kicked at his opponent’s knee-joint with the same foot. The Japanese somersaulted, ending flat on his back, and the foot thudded across his windpipe.

For a moment they lay there and then both men scrambled to their feet grinning widely. “In other circumstances, and had the blows been delivered with full force, my assistant would now be dead,” Yoshiyama said simply.

Adams picked up a towel, started to wipe sweat from his face and caught sight of Mallory in the gallery. He nodded briefly, said something to Yoshiyama and moved across to the door. Mallory met him in the corridor outside.

“What are you trying to do, go out in a blaze of glory?”

Adams grinned. “Every so often I get so sick of the sight of that damned desk that I could blow my top. Yoshiyama provides a most efficient safety-valve.” He ran a hand over his right hip and winced slightly. “That last fall hurt like hell. I must be getting old.”

As they mounted the stairs at the end of the corridor, Mallory thought about Adams. One of the best agents the department had ever had; all the guts in the world and a mind like a steel trap until the night he’d got too close for someone’s comfort and they’d tied a Mills bomb to the handle of his hotel bedroom in Cairo.

And now he was a desk man, running 63, the intelligence section that was the pulse-beat of the whole organisation. Some people would have said he was lucky, but not Adams.

He opened a door and walked through a small, neat office. A middle-aged, desiccated-looking spinster with neat grey hair and rimless spectacles sat behind the typewriter. She glanced up, an expression of disapproval on her face, and Adams grinned.

“Don’t say it, Milly. Just tell them I’m ready.”

He led the way into his own office. Like Sir Charles’s, it commanded a fine view of the river, the desk standing by the window. He opened a cupboard, took out a heavy bathrobe and pulled it on.

“Sorry about the delay. I thought Sir Charles would keep you for an hour at least.”

“More like fifteen minutes,” Mallory said. “He always goes straight to the heart of things with the sticky ones.”

“I wouldn’t call it that,” Adams said. “Interesting more than anything else. Whole thing could be just a storm in a teacup. Let’s go into the projection room.”

He opened the far door and they descended a few steps into a small hall. There were several rows of comfortable seats and a large screen. The place was quite deserted. They sat down and Mallory offered Adams a cigarette.

“Any gaps in this one?”

Adams exhaled with a sigh of pleasure and shook his head. 1 don’t think so. Nothing important, anyway. Has the old man told you much?”

“He’s outlined the job, told me who the principals are. No more than that.”

“Let’s get started, then.” Adams turned and glanced up at the projection box where a dim light showed. “Ready when you are.”

A section of film started to run a few moments later. It showed a submarine entering port slowly, her crew lining the deck.

“To start with5that’s what all the fuss is about,” Adams said. “L'Alouette. Taken at Oran a couple of years ago.”

“She looks rather small. There can’t be more than a dozen men on deck.”

“Originally a German U-boat. Type XXIII. Just over a hundred feet long. Does about twelve kilometres submerged. Crew of sixteen.”

“What about armament?”

“Two twenty-one-inch torpedoes in the bow and she doesn’t carry spares.”

"Doesn’t leave much room for mistakes.”

Adams nodded. “They never really amounted to anything. This one was built at Deutsches Werft in 1945 and sunk with all hands in the Baltic. She was raised in '46, refitted and handed over to the French.”

The film ended and a slide appeared. It showed a young French naval officer, eyes serious beneath the uniform cap, the rather boyish face schooled to gravity.

“Henri Fenelon, full lieutenant. He’s her commander. Age twenty-six, unmarried. Born in Nantes. Father still lives there. Runs a small wine-exporting business.”