“If Walter’s right, then clearly someone in Russian intelligence has a sense of humor,” said Maugham. “The idea of the British government paying off the KGB to stop it from leaking secrets about its number one defector is nothing short of hilarious. At least, it would be if it wasn’t me who was being asked to pay up.”

“Quite,” said Sinclair.

“And Hebel is the man who was in possession of the incriminating photograph that Anthony bought from Willie’s nephew, Robin,” said Reilly. “Is that right? For a thousand pounds.”

“Yes,” said Maugham. “I’m sorry about that, Anthony. You must let me give you the thousand pounds you paid him for it.”

“Please don’t concern yourself too much, Willie,” said Blunt. “As you know, this is not so much an occupational hazard as a constitutional one. The picture and the negative were both purloined from my flat several months ago. In my work as director of the Courtauld Institute I have to entertain a great many students. Sadly, I think one of them must have stolen it and sold it to this awful man. I do have half an idea of who it might have been. An Austrian boy. Which makes it even more disappointing. He’s one of my most promising students.”

“You know this fellow reminds me of the chap in the Sherlock Holmes story,” said Sinclair. “‘The Adventure of Charles Augustus Milverton.’”

Reilly smiled calmly. “Yes, of course. The king of blackmailers. Rather a good tale that one, I always thought.”

“Milverton was based on a real blackmailer, by the way,” added Blunt. “A man called Howell who was blackmailing the artist Dante Gabriel Rossetti. Howell was found with his throat cut and half a sovereign in his mouth. Which seems fitting, somehow.”

“I wish someone would cut this man Hebel’s throat,” said Maugham. “I suggested to Walter that he should kill him, but alas he declined. Why don’t you have your two friends from Portsmouth pick him up and go to work on him with a red-hot travel iron. It seems to me that you could get all the answers you need from him that way.”

“I don’t think the French would like that very much,” said Reilly. “We’re getting on rather well with them right now, what with all this Suez business. Which makes a very pleasant change. For once we’re on the same page. They wouldn’t like it at all if we acted in such a high-handed fashion as you describe, Willie.”

“Besides,” added Sinclair, “we risk Hebel’s masters responding to that by simply sending one of the tapes to the Americans. Which would be a disaster. That’s the risk you take when you call the blackmailer’s bluff. That the whole thing goes pear-shaped.”