"It is all very mysterious," I put in, because my eccentric friend had been silent for quite a long time, while his attention was entirely taken up by the fashioning of a whole series of intricate knots. "I am afraid that I was one of those who blamed the police for not directing their investigations sooner in the direction of the second visitor. He seems to me much more mysterious than the first. We know who the first one was----" "Do we?" he retorted with a chuckle. "Or rather, do you?" "Well, of course, it was Arthur Leighton," I rejoined impatiently. "Mrs. Tufnell saw him----" "She didn't," he broke in quickly. "The house was pitch-dark; she heard voices and she asked Ann whether she was speaking to Mr. Leighton." "And Ann said yes!" I riposted. "She said yes," he admitted with an irritating smile. "And Leighton himself in his evidence----" "Leighton in his evidence," the funny creature broke in excitedly, "admitted that he had called at the house, he admitted that he remembered vaguely that Ann Weber told him that Mr. Jessup had decided not to see him, and that to celebrate the occasion he got the girl to make him a whisky toddy. But, apart from these facts, he only had the haziest notions as to the time when he came and when he left or how long he stayed. Nor were his precious friends at the Café Royal any clearer on that point. They had all of them been drinking, and only had the haziest notion of time until twenty minutes to ten, when they got hungry and wanted their supper." "But what does that prove?" I argued with an impatient frown.