had called at the Savoy Hotel upon a travelling American, who had written to the Embassy asking for some advice as to introducing American patents into Great Britain and France. He left there to meet his chief, who was dining down in Kensington, with the intention of returning at once to join the Duchess of Devenham’s theatre party. He was in no manner of trouble. It was not suggested that any one had any cause for enmity against him. Yet this attack upon him must have been carefully planned and carried out by a person of great strength and wonderful nerve. The newspaper-reading public in London love their thrills, and they had one here which needed no artificial embellishments from the pens of those trained in an atmosphere of imagination. The simple truth was, in itself, horrifying. There was scarcely a man or woman who drove in a taxicab about the west end of London during the next few days without a little thrill of emotion. The murder of Mr. Richard Vanderpole took place on a Thursday night. On Monday morning a gentleman of middle age, fashionably but quietly dressed, wearing a flower in his buttonhole, patent boots, and a silk hat which he had carefully deposited upon the floor, was sitting closeted with Miss Penelope Morse. It was obvious that that young lady did not altogether appreciate the honor done to her by a visit from so distinguished a person as Inspector Jacks! “I am sorry,” he said, “that you should find my visit in the least offensive, Miss Morse. I have approached you, so far as possible, as an ordinary visitor, and no one connected with your household can have any idea as to my identity or the nature of my business. I have done this out of consideration to your feelings. At the same time I have my duty to perform and it must be done.” “What I cannot understand,” Penelope said coldly, “is why you should bother me about your duty. When I saw you at the Carlton Hotel, I told you exactly how much I knew of Mr. Hamilton Fynes.” “My dear young lady,” Inspector Jacks said, “I will not ask for your sympathy, for I am afraid I should ask in vain; but we are just now, we people at Scotland Yard, up against one of the most extraordinary problems which have ever been put before us. We have had two murders occurring in two days, which have this much, at least, in common--that they have been the work of so accomplished a criminal that at the present moment, although I should not like to tell every one as much, we have not in either case the ghost of a clue.” “That sounds very stupid of you,” Penelope remarked, “but I still ask--” “Don’t ask for a minute or two,” the Inspector interrupted. “I think I remarked just now that these two crimes had one thing in common, and that was the fact that they had both been perpetrated by a criminal of unusual accomplishments. They also have one other point of similitude.” “What is that?” Penelope asked. “The victim in both cases was an American,” the Inspector said.