"It sounds," George said, "as if today was the high point in his life."

"How far have we got?" Maxim asked.

"Four years ago. There's nothing after he left the arms business. Despite what some people think, we don't keep files on everybody in the country."

George asked: "What about Canada? If he was there long enough to buy a suit he must have had a job. They wouldn't let him stay, otherwise."

"He wasn't working in any defence industry. The Mounties would have vetted him and asked us what we knew."

"Unless your people lost the letter."

"Unless our people lost the letter," Agnes agreed calmly.

George made a noise that could have been apologetic. "And no connection with Professor Tyler?"

"There's no hint of it. Farthing seems to have spent his working life in the north, and Tyler's always lived in the south, hasn't he? Cambridge and London?"

"Yes. Where the bloody hell are our drinks?" George leant round sharply and almost butted the steward in the stomach. With dreadful precision, the old man put down the glasses in the wrong places, flooded George's whisky with too much water and went away.

"Just ain't yer night, is it, me ole china?" Agnes said. "Cheers."

George took a vast mouthful of his drink. "I want those four years filled in."

"There's two ends to the business," Agnes said.

"I know. Harry's taking the other one."

Maxim looked up. "Am I?"

"He mentioned the anti-tank mortar trials, didn't you say?"

"Yes, he said that-"

"I know. They aren't secret, but they aren't news either. There hasn't been anything in the papers."

"He'd still have friends in the arms business."

"That's probably it. Tyler's going to watch a demonstration by the development unit at Warminster on Monday. You'd better go, too. Get onto Sir Bruce and have yourself fixed up as Tyler's temporary ADC. And when you're with him, listen."

"That's all?"

"I don't know." George looked uneasy. "And guard his back. Where there's a drill grenade there might be a real one…"

Just past Andover, they overtook a convoy of Bedfords and Land-Rovers.›From the back seat of their own chauffeur-driven car, Maxim watched the dull black-and-green vehicles, feeling an unexpected pang of pleasure. Absurd, but it was partly a sense of coming home: Salisbury Plain, ringed with Army camps, covered in ranges, and with Stonehenge seemingly shunted off into one corner, was home to any infantryman.

Professor Tyler commented: "Familiar country, I imagine."

"I'd take a penny for every pace I've marched across Wiltshire. Were you here in the war?" Maxim wasn't sure whether to call Tyler 'sir' or 'professor' or just 'John', as Tyler himself had suggested. So for most of the journey he hadn't called him anything.

"Only for a few weeks," Tyler said. "When we were winding up for D-Day. I did most of my training in Cumberland, before I went to Africa."

"I remember."

Tyler turned to look at him and asked in his serious deep voice: "Have you really read The Gates?"

"I read it when I was at school. Only in paperback, I'm afraid, sir. It might even have been one of the reasons I joined the Army. " The 'sir' had slipped out naturally: now he was talking to a famous soldier. And not flattering him, either. The Gates of the Grave, in particular its chapters on Tyler's adventures with the bearded land-pirates of the Long Range Desert Group working deep behind Rommel's lines, had hit young Harry Maxim like a star shell. This was war as every schoolboy wanted it to be. But unlike most other schoolboys, Maxim had gone on to re-live Tyler's experiences. Now he too had driven armed trucks across hostile deserts, had lifted land-mines with his own hands, had shot his way out of ambush.

For that very reason, he had never dared re-read the book. He was frightened that he might find giveaway hints that showed Tyler had faked or exaggerated parts of it. You don't always want to meet your first love twenty years later.

"Do you know why I wrote that book?" Tyler gave one of his little grunt-chuckles. "To finance my first divorce. Well, at least it did that. But if you're thinking of an academic career, don't ever write anything that sells well. That book kept me out of any Cambridge job for years. Hell hath no fury like a Senior Common Room seeing somebody actually make some money by publishing." He chuckled again and hunched himself down into a shabby-expensive plaid overcoat. "Are those pullovers as warm as they're supposed to be?"

Maxim was wearing the everyday Army dress of a green 'woollie-pullie' – it was the first time he'd been in uniform for weeks – and carrying a combat jacket of Disruptive Pattern Materials (the Army's abbreviation of 'camouflage') which had a pistol in the side pocket. He didn't know if Tyler knew about that.

"They're pretty good. I think they're very closely knit."

"I suppose I'm growing old, but all these pullovers and combat kit jackets – you call it DPM, don't you? – it makes the Army seem rather casual."

"I hadn't thought that 8th Army set any very high standards of dress in its time, sir?"

"Good Lord, no. All those corduroy bags and suede brothel-creepers, and Monty with two badges in a Tank Regiment beret he wasn't entitled to wear… This country's always had a tradition of making the word 'uniform' quite meaningless when applied to military clothing. But at least there was a pretence of trying. Twenty-five years ago you couldn't go through a mainline station without seeing dozens of soldiers and airmen, all in their walking-out uniforms or whatever it was called."

"I remember."

"Now we forbid people to wear uniform when travelling, or after tea, or.. I suppose defence was still popular in those days…"

"But it's a thin DPM line of heroes when the guns begin to shoot."

Tyler didn't answer and perhaps hadn't heard. He had turned away to watch the damp plain drifting past outside. Or perhaps something far further away.

Like most Army camps, Warminster barracks is a collection of unnaturally clean buildings of all ages and sizes laid out at random: a model railway village set up by a child too young for model railways. The commandant of the School of Infantry gave them a drink and chatted to Tyler throughout lunch, then passed them on to the lieutenant-colonel in command of the development unit itself.

So far, Maxim had met nobody he knew personally, but the Army grapevine had made sure everybody knew about him, once they'd heard that he would be shepherding Professor Tyler. Several officers who had never met Jenny said they were sorry to hear of her death. Maxim was growing a mental scar tissue, finding phrases to fend off commiserations that nobody really wanted to make. But suddenly, when they were drinking coffee in the ante-room, he felt a flush of anger.

God damn it, is having my wife killed the only memorable thing I've done in this Army?

It was a relief to get out into the damp cold air again.

The firing point was up on the edge of the plateau, a bleak exposed area where no commander would ever set up his mortars for real. But it gave a view of the target area, and visitors liked to see two bangs for the price of one. There was a small but permanent plank grandstand for them, already nearly filled with senior officers, including the RAF and Navy.

Maxim and Tyler chose gumboots from neat rows laid out for spectators, and clumped across the grey winter grass that looked dry and brittle even when it was squishy-wet under foot. Two of the senior officers came down to shake Tyler's hand and a sergeant appeared with an expensive camera and started taking pictures.

At that, Maxim decided that Tyler couldn't have been safer locked up in the Bank of England, and faded back to talk to one of the organising officers, a Gunner major called Tom Shelford, and the first one Maxim could really say he knew. They'd worked together in Germany.