“A Dutch diamond merchant called Witt came to live in the flats. Wilton got to know him, prescribed for a cold or something. Witt took to the doctor, made friends, heard about his troubles, offered to get him a berth in the Dutch colonies, gave him two or three rough diamonds--a delicate way of giving him money, I suppose. Then one morning the valet--service flats they are--coming into Witt’s rooms found him heavily asleep. He’d been chloroformed. There was that pad on his pillow.” Reggie took up the box in which the cotton-wool and the skeleton key lay. “Don’t shake it,” said the superintendent. “Do you see those scraps of tobacco? That’s important. The bureau in which Witt kept the diamonds he had with him had been forced open and the diamonds were gone. Witt sent for the police. Now you see that tobacco on the cotton-wool. The inspector spotted that. The cotton-wool must have been handled by a man who smoked that tobacco. Most likely carried it in the same pocket. Unusual stuff, isn’t it? Well, the inspector remarked on that to Witt. Witt was horrified. You see it’s South African tobacco. And he knew Wilton used the stuff. There was some spilt in the room, too.” “Have you got that?” said Reggie. “No. I don’t think it was produced. But our man saw it, and he’s reliable. Then a Dutch journalist dropped in. He was just over in England. He’d called on Witt late the night before and couldn’t make him hear. That surprised him because as he came up he’d seen some one coming out of Witt’s rooms, some one who went into Wilton’s. That was enough to act on. Wilton was arrested and his flat was searched. Tucked away in the window seat they found the diamonds and that skeleton key. He stood his trial yesterday, he made no defence but to swear that he knew nothing about it. The evidence was clear. Witt--he must be a soft-hearted old fellow--Witt tried to let him down as gently as he could and asked the judge to go easy with him. Old Borrowdale gave him five years. A stiff sentence, but the case itself would break the man’s career, poor chap. A bad business, sir, isn’t it? Impudent, ungrateful piece of thieving--but he might have been honest enough if he could have made a living at his job.” Mr. Fortune did not answer. He was looking at the key. He set it down, took up a magnifying glass, carried the box to the light and frowned over the cotton-wool. “What’s the matter with it, sir?” “The key,” Mr. Fortune mumbled, still studying the cotton-wool. “Why was the key made in Germany? Why does Dr. Horace Wilton of Harley Street and Bloomsbury use a skeleton key that was made in Solingen?” “Well, sir, you can’t tell how a man comes by that sort of stuff. It goes about from hand to hand, don’t it?” “Yes. Whose hand?” said Reggie. “And why does your local expert swear this is South African tobacco? There is a likeness. But this is that awful stuff they sell in Germany and call Rauch-tabak.” Bell was startled. “That’s awkward, sir. German too, eh?”