At ten he rang for coffee and at a quarter past he rang to have it taken away, cold and untouched. Graham, his butler, looked concerned but said nothing as he came to and fro. By eleven, however, he could no longer prevent himself from intervening, and presented himself unbidden in the dark oak doorway of the room.

At that moment Lenox had just taken up residence at his desk, where he was looking across the street at the bookshop.

“May I get you anything else, sir?” Graham said.

“No, no,” said Lenox distractedly, still peering through the rain-touched window.

“If I may venture to say so, sir, you seem anxious.”

In many of the aristocratic Mayfair households surrounding Hampden Lane, such a statement would have seemed like the highest impertinence. Lenox and Graham had a long and complex history, though, and in the end were friends more than master and man. While Graham, a sandy-haired man with perfectly arranged clothes and a strong, utterly honest face, always spoke and behaved respectfully, he never hesitated to disagree with Lenox, often helped the detective in his work, and even, on rare occasions, spoke with the frankness he just had.

“Eh?” said Lenox, at last looking up. “Oh, no, Graham-no, thank you, I’m quite all right.”

“Will you take your lunch here in the library, sir?”

“No,” said Lenox. “Thanks, I’m having lunch in the City, actually. I shall be glad to get on the other side of these four walls.”

“Indeed, sir,” said Graham. He paused before adding, “I am in the hall if you require anything.”

“Thank you,” said Lenox.