"I hear strange tales about goings-on in wildest Wiltshire," Sladen said. "Are you going to find yourselves all over the front page of the Express? "

"I don't think so." George sounded confident. "All that happened was that somebody fired off a shotgun in front of a hotel at some Godawful hour of the night and has been charged with this and that. That's not exactly stop-the-presses, and they can't comment on a case that's sub judice anyway."

"But our Professor Tyler was inside at the time, was he not?"

George shrugged. "What's secret about that? We've asked all three services to publicise his visits wherever he goes. That way, we keep the spotlight on conventional warfare."

Sladen frowned warningly, and drew them away from the crowd with delicate gestures of his cup and saucer.

"And," Agnes chipped in, "we now know we've got the fastest gun in Whitehall." She and Maxim exchanged rather false smiles.

"Nobody got killed," George said. "And Harry can also look up records. Would you like to hear what he found, or would you prefer to go on criticising?"

Agnes made a little curtsy.

Maxim put his cup down on the edge of a desk and took out a notebook.

"Gerald Jackaman. He was at Oxford when the war started. He tried to join up then, but they had too many people trying to get in so they told him to go back and do his last year. Anyway, the whole thing was going to be over by Christmas."

"I'm quite sure," George said, "that Odysseus's last words to Penelope, as he went off to Troy were: 'Don't worry, old girl, I'll be home by Christmas'."

Sladen said: "Since it was to be approximately thirteen hundred years to the first Christmas, he was giving himself a fair margin of error. I do apologise, Major."

Maxim was wearing a small patient smile. "He joined up in June 1940. He was commissioned into the Rifle Brigade in October. In December he smashed up a knee playing rugger."

"A bit bloody silly," Agnes suggested.

George said: "Good for morale, to let the troops tear an officer to pieces occasionally."

"Reading between the lines," Maxim went on, "I gather he wasn't seen as any ball of fire, so when his knee didn't look like repairing properly, they gave him a medical discharge. He took the civil service exam and was accepted by the Foreign Office. He spoke French very well, so he was doing liaison work with the Free French. Then, in January 1943 he went to Algiers with Harold Macmillan. Churchill sent out a small Foreign Office mission to look after our political interests in North Africa, and Jackaman was part of it-"

"You didn't get that from Army records, did you?" Sladen said.

George said: "No, the FO. I squared it. Good practice, for Harry to find his way around."

"So where could he have met Tyler?" Sladen asked.

"They were both in North Africa at that time, but Tyler was with 8th Army, down in Libya and Tunisia. He was evacuated home a month or so after Jackaman got to Algiers. After that, they were both in Britain in early '44, but Jackaman went to Washington in May and stayed until after the war."

Sladen grunted.

"And what about Bob Bruckshaw?" Agnes asked.

"There was no Robert Bruckshaw in the Army at that time."

Isolated in a corner, the four of them were getting curious glances from the rest of what was, after all, supposed to be a General Exchange of Views. A couple of teacups were rattled, but George ignored them.

"And now let's hear the news summary from Liza Doolittle."

Agnes smiled and recited from memory. "Robert Bruckshaw died in Montreal General Hospital, cirrhosis all right, in December two years ago. He gave his age as fifty-eight and birthplace as Yorkshire, no next of kin. The only visitors anybody can remember were a couple of workmates – he'd been driving a truck on a building site. And yes, Charles Farthing was also a patient there at the time."

Maxim said: "There's no Bruckshaw mentioned in The Gates of the Grave, either. Nor a Jackaman."

There was a pause. Then George said: "Bruckshaw must have changed his name. God knows, so would I if I had to go to Canada."

Agnes nodded. "I've asked the Mounties to check it. They're good when they get their snow-shoes on. But it seems that name changes are registered province by province, not nationally, so they could have to try right across the country and going back thirty years. And that's assuming he changed it legally and in Canada. If not…"

"So where," Sladen asked, "does that leave us?"

"Just thankful that nobody's been killed," George said.

"Shall we re-join the Mad Hatters?"

The PM owned a cat, a fat multi-coloured ex-female, who had taken a liking to Maxim's office – perhaps, he thought ruefully, because it was one of the least busy in the house. She would scratch on the door until he opened it, and rush in staring around suspiciously, like a wife expecting to see Another Woman diving out of the window. Then she curled up on whatever papers Maxim was trying to read and went to sleep.

She was there that morning when George rang through to say that if Maxim wasn't too busy – he was trying to read as much of the RUSI Journal as the cat allowed – he wanted to pop up and see him.

He arrived a minute later, shutting the door firmly behind himself. The cat looked at him balefully.

"Do you like cats?" George asked.

"This one doesn't give you a choice."

"She's giving me one. However… this just might be as important as the old air-dog thinks it is, or it may be sheer bull." He gave Maxim the Kensington address of Wing-Commander Neale, RAF (Retired) and now MP for a West Country constituency. "He's a bit of a pain except when he's talking about tourism or defence, but he's one of the few MPs who still think this country's worth defending, so we toss him a bottle of rum from time to time. He wants to see you, or at least 'that new Army chap I hear you've got at Number 10'. Try not to knock any of his tail feathers off and call me if it's anything vital."

Maxim was already putting on his coat. "Should I take the gun?" He nodded at the squat little safe the Housekeeper's Office had found for him.

George gave it a moment's thought and shook his head. "It shouldn't come to anything like that." He turned out to be wrong.

Neale lived in one of a row of what estate agents call 'bijou mews cottages'. It had a neat doll's-house look to it, everything slightly smaller than life and brightly painted. Apricot walls, white woodwork, a blue front door with bits of black ironwork. All rather wasted, since it looked across the humpy cobblestones to nothing more than a drab line of lock-up garages.

Neale himself opened the door and held it on the chain.

"I'm Major Maxim from Downing Street."

Sharp blue eyes looked him up and down. "Can I see your ID, please, Major?"

The Wing-Commander was in his late fifties, a solid but fit-looking man with a good head of very clean white hair. His face was square and covered with deep creases, as if made from expensive leather. He wore a polo-necked cashmere sweater and checked slacks.

He looked carefully at Maxim's identity card and let him into the little dark hallway, double-locked the door, then led the way through to a living-room made from two small rooms opened right through.

"Sit down, Major." Neale indicated just which chair. "Would you like a cup of coffee?"

"If it's going, sir," A silly answer since it was already waiting: plain white bone china pot, two cups, two colours of sugar. It belonged with the fresh paint outside, the precisely arranged little seascapes and brass ornaments around him now. A whisper of money, but money carefully spent. The Wing-Commander was divorced, and there would be a home in his constituency to keep up, and with no grace and favour directorships in the city, there might not be all that much to spend.