Finally I was ushered into a room labeled Bureau du Commissaire, a smallish office with a solitary porthole window overlooking the river and the Latin Quarter. There were shelves on three sides half filled with folders, which two men were loading up on trolleys to transport to another location. Massu was standing, leaning over his desk. His hair was neatly combed, the homburg hanging from a stand in the corner. He didn’t look up when I came in, but gestured for me to approach while instructing the other men to leave us. Pictures of Vennet’s apartment were fanned out on the desk in front of him. It had been photographed from every possible angle. There were shots of Vennet’s body, lying fully dressed on the bed in the fetal pose in which I’d found him. There was one photograph so gruesome I had to look away: a shot of his eyeless face.

Massu must have noticed me flinch. “Once seen, never forgotten,” he said. “Note the minimal bleeding from the eyes. No laceration of the epidermis inside or around the sockets. Eye injuries don’t bleed much, as a rule, but there is evidence of abrasion around the neck”—he pointed with his index finger—“indicating the victim’s head was immobilized. What does that tell you?”

“That he was alive when his eyes were gouged?”

“Precisely. The poor man was tortured.” Massu sat down in his deskchair and began stroking his chin. “But why?” I had no reply. He took a manila folder out of a drawer, opened it, and began scanning its contents with a raised eyebrow, emitting a series of staccato grunts. He seemed the kind of man who was never rattled, whose mind was always turning, whose slight smile disappeared rarely. “Tell me, monsieur,” he said, “what were you doing at the auction yesterday?”

“I was interested in the Baudelaire manuscript. I’m a writer, and something of a Baudelaire scholar.”

“Why did you follow Vennet afterward?”

“I happened to be walking behind him after the auction and saw that he was being followed by two people, one of whom was you, of course, although I didn’t know you were a policeman. But the other one was the man he’d beaten to the prize. It seemed suspicious to me. When I saw that he was in the bookshop, I went in to warn him that he was being followed.”

“After you fled the scene, Vennet took your advice and gave us the slip. So I was unable to protect him, which was why I was there in the first place. By the time I tracked him down he was already dead. So, in a way, if it wasn’t for your interference, Vennet might still be alive. Then, wonder of wonders, you turn up the following day at the scene of the crime. How does that happen?”

“I didn’t murder Vennet, which is what you seem to be implying.”