“I must apologize for my recent actions,” he said at last to Hanslet. “I think you will understand them when I have explained my reasons to you. I was anxious to come here without anybody suspecting my presence. I had formed a theory as to the motive of the murders in Praed Street. Harold, my boy, tell Inspector Hanslet, as concisely as you can, the facts about the arrest and trial of Dr. Morlandson.”

Harold obeyed, and as he finished Hanslet nodded. “I remember the case vaguely,” he said. “But I don’t see⁠—”

The Professor interrupted him. “I happened to be the foreman of the jury. When you mentioned the name of Copperdock the other night, I fancied that it was familiar to me. Eventually I remembered that a man of that name had been one of the jurymen. More out of curiosity than anything else, I took steps to discover the names of the remainder of the panel. They were Tovey, Colburn, Pargent, Martin, Goodwin, and five others, whom I am informed have since died.”