On the drive back, Duncan, deeply perturbed and trying not to show it, pumped David for information.

"It was an interesting evening, but it’s left me with a problem."

"What’s that?"

"I-eh-wasn’t completely sure which murder of mine they were talking about."

"Do you mean you’re a serial killer?"

Duncan gulped. He hadn’t meant that at all. "I’ve never thought of myself as one." Recovering his poise a little, he added, "A thing like that is all in the mind, I suppose. Which one do they have me down for?"

"The killing of Sir Jacob Drinkwater at the Brighton Civil Service Conference in 1995."

Drinkwater. He had been at that conference. He remembered hearing that the senior civil servant at the Irish Office had been found dead in his hotel room on that Sunday morning. "That was supposed to have been a heart attack."

"Officially, yes," said David.

"But you heard something else?"

"I happen to know the pathologist who did the autopsy. A privileged source. They didn’t want the public knowing that Sir Jacob had actually been murdered, and what means the killer had used, for fear of creating a terrorism panic. How did you introduce the cyanide? Was it in his aftershave?"

"Trade secret," Duncan answered cleverly.

"Of course the security people in their blinkered way couldn’t imagine it was anything but a political assassination. They didn’t know you’d had a grudge against him dating from years back, when he was your boss in the Land Registry."

Someone had their wires crossed. It was a man called Charlie Drinkwater who’d made Duncan’s life a misery and blighted his career. No connection with Sir Jacob. Giving nothing away, he said smoothly, "And you worked out that I was at the conference?"

"Same floor. Missed the banquet on Saturday evening, giving you a fine opportunity to break into his room and plant the cyanide. So we have motive, opportunity…"

"And means?" said Duncan.

David laughed. "Your house is called The Laurels, for the bushes all round the garden. It’s well known that if you soak laurel leaves and evaporate the liquid, you get a lethal concentration of cyanide. Isn’t that how you made the stuff?"

"I’d rather leave you in suspense," said Duncan. He was thinking hard. "If I apply to join the club, I may give a demonstration."

"There’s no if about it. They liked you. You’re expected to join."

"I could decide against it."

"Why?"

"Private reasons."

David turned to face him, his face creased in concern. "They’d take a very grave view of that, Duncan. We invited you along in good faith."

"But no obligation, I thought."

"Look at it from the club’s point of view. We’re vulnerable now. You’re dealing with dangerous men, Duncan. I can’t urge you strongly enough to co-operate."

"But if I can’t prove that I killed a man?"

"You must think of something. We’re willing to be convinced. If you cold shoulder us, or betray us, I can’t answer for the consequences."

A sobering end to the evening.

For the next three weeks he got little sleep, and when he did drift off he would wake with nightmares of fingers pressing on his arteries or skene-dhus being thrust between his ribs. He faced a classic dilemma. Either admit he hadn’t murdered Sir Jacob Drinkwater-which meant he was a security risk to the club-or concoct some fake evidence, bluff his way in, and spend the rest of his life hoping they wouldn’t find him out. Faking evidence wouldn’t be easy. They were intelligent men.

"You must think of something," David Hopkins had urged.

Being methodical, he went to the British Newspaper Library and spent many hours rotating the microfilm, studying accounts of Sir Jacob’s death. It only depressed him more, reading about the involvement of Special Branch, the Anti-Terrorist Squad and MI5 in the official investigation. Nothing he had read, up to and including the final pronouncement in the papers that the death had been ruled a heart attack and the investigation closed, proved helpful to him. How in the world would he be able to acquire the evidence the club insisted on seeing?

More months went by.

Duncan weighed the possibility of pointing out to the members that they’d made a mistake. Surely, he thought (in rare optimistic moments), they would see that it wasn’t his fault. He was just an ordinary bloke caught up in something out of his league. He could promise not to say anything to anyone, in return for a guarantee of personal safety. Then he remembered the eyes of some of those people around the table, and he knew how unrealistic that idea was.

One morning in May, out of desperation, he had a brilliant idea. It arose from something David Hopkins had said in the car on the way home from the club: "Do you mean you’re a serial killer?" At the time it had sounded preposterous. Now, it could be his salvation. Instead of striving to link himself to the murder of Sir Jacob, he would claim another killing-and show them some evidence they couldn’t challenge. He’d satisfy the rules of the club and put everyone at their ease.

The brilliant part was this. He didn’t need to kill anyone. He would claim to have murdered some poor wretch who had actually committed suicide. All he needed was a piece of evidence from the scene. Then he’d tell the Perfectionists he was a serial killer who dressed up his murders as suicides. They would be forced to agree how clever he was and admit him to the club. After a time, he’d give up going to the meetings and no one would bother him because they’d think their secrets were safe with him.

It was just a matter of waiting. Somebody, surely, would do away with himself before the July meeting of the club.

Each day Duncan studied The Telegraph, and no suicide-well, no suicide he could claim was a murder-was reported. At the end of June, he found an expensive-looking envelope on his doormat and knew with a sickening certainty who it was from.

The most perfect club in the world

takes pleasure in inviting

Mr. Duncan Driffield

a prime candidate for membership

to present his credentials

after dinner on July 19th, 7:30 for 8pm

Contact will be made later

This time the wording didn’t pamper his ego at all. It filled him with dread. In effect it was a sentence of death. His only chance of a reprieve rested on some fellow creature committing suicide in the next two weeks.

He took to buying three newspapers instead of one, still with no success. It seemed as if there was no way out. Mercifully, and in the nick of time, however, his luck changed. News of a suicide reached him, but not through the press. He was phoned on the afternoon of the 19th by an old civil service colleague, Harry Hitchman. They’d met occasionally since retiring, but they weren’t the closest of buddies, so the call came out of the blue.

"Some rather bad news," said Harry. "Remember Billy Fisher?"

"Of course I remember him," said Duncan. "We were in the same office for twelve years. What’s happened?"

"He jumped off a hotel balcony last night. Killed himself."

"Billy? I can’t believe it!"

"Nor me when I heard. Seems he was being treated for depression. I had no idea. He was always cracking jokes in the office. A bit of a comedian, I always thought."

"They’re the people who crack, aren’t they? All that funny stuff is just a front. His wife must be devastated."

"That’s why I’m phoning round. She’s with her sister. She understands that everyone will be wanting to offer sympathy and help if they can, but for the present she’d like to be left to come to terms with this herself."

"Okay." Duncan hesitated. "This happened only last night, you said?"

Already, an idea was forming in his troubled brain.

"Yes. He was staying overnight at some hotel in Mayfair. A reunion of some sort."