“Certainly. Clayton had no occasion to suspect Margate, whom he knew only as Doctor Guelpa. He complied, of course, and Margate invited him to his suite. Then, passing back of him, he threw one arm around his head and over his mouth, at the same time injecting into his neck a quantity of the same swiftly acting drug with which he had overcome Patsy Garvan earlier in the evening.” “Clayton has told me about that.” “It was done in a couple of minutes,” Nick went on. “Margate then stripped Clayton of his outside garments, exchanging them for his own, and placed his senseless form on the bed.” “But what motive had he?” questioned Langham. “Why did he not flee at once after receiving the warning?” Nick laughed a bit derisively. “You don’t know this rascal, Mr. Langham,” he replied. “I now know more about him than I then did. He turned that trick only because he was short of funds. He then went down to the hotel office, a human counterfeit of Clayton, with the intention of stealing the money from the hotel vault.” “Ah, I see,” Mr. Langham nodded. “A rascal, Carter, indeed.” “My timely arrival with Patsy at just that moment prevented his design,” said the detective. “He had no sane alternative, when I called to him, but to accompany us to the suite. My assistant then made a hurried examination of the man on the bed, and he at once inferred that Margate had committed suicide.” “I suppose it appeared so,” Mr. Langham allowed. “In the meantime,” Nick added; “the supposed Clayton cried that he must telephone the good news to his mother and to Mademoiselle Falloni, whose stolen jewels we had just recovered. He hurried from the room, as if to do so. We now know that he hurried from the house, and that is the last we saw of him. But the whole business from beginning to end occurred in less than fifteen minutes, Mr. Langham, and no detective on earth, unless gifted with clairvoyance, would have suspected the trick.” “I admit, of course, that it would have seemed impossible,” bowed Langham. “Now, sir, let me tell you what I since have learned about this crook,” said Nick. “I have looked up his record abroad. He twice had been convicted and sent to prison. He at one time was associated in Paris with the notorious Doctor Leon Deverge, who was executed two years ago for wholesale murder by means of drugs and poisons, of which he had made so profound a study that he knew much more of their subtle and deadly qualities than has been learned by any of his contemporaries.” “I remember having read of the man.” “This notorious physician and chemist imparted to David Margate much of his dangerous knowledge, and the career of the latter has always been one of vice and crime. It has been accomplished with such exceeding craft and cunning, moreover, that he most of the time has completely baffled the police. I admit that Margate is a terrible menace to society and to----”