“But the thing is impossible, Thorndyke,” I said. “Not only did the witnesses recognize their own signatures and the painter’s greasy fingermarks, but they had both read the will and remembered its contents.”

“Yes; that is the interesting feature in the case. It is a very pretty problem. I shall give you a last chance to solve it. Tomorrow evening we shall have to give a full explanation, so you have another twenty-four hours in which to think it over. And, meanwhile, I am going to take you to my club to dine. I think we shall be pretty safe there from Mrs. Schallibaum.”

He sat down and wrote a letter, which was apparently quite a short one, and having addressed and stamped it, prepared to go out.

“Come,” said he, “let us away to ‘the gay and festive scenes and halls of dazzling light.’ We will lay the mine in the Fleet Street pillar box. I should like to be in Marchmont’s office when it explodes.”