"So did I," said Durwin once more; "but I thought Sir Charles might have used it. You say he did not, therefore the scent is a clue." "It does not lead to the indictment of Mrs. Brown, however, sir," said Tenson thoughtfully, "since she had no perfume of that sort about her. But she must have killed Sir Charles, for she was the last person who saw him alive." "She may come forward and exonerate herself," suggested Dan after a pause, "or she may have left her address with Sir Charles." "I have glanced through the papers on the desk and can find no address," was the Inspector's reply; "yet, if she gave it to him, it would be there." Durwin meditated, then looked up. "As she was the mother of the man in Sir Charles's employment who was drowned," he said in his harsh voice, and now very official in his manner, "in the offices of the company who own the steamers--Sir Charles was a director and chief shareholder, I understand from his secretary, Mr. Penn--will be found the drowned man's address, which will be that of his mother." "But I can't see what motive Mrs. Brown had to murder Sir Charles," remarked Dan in a puzzled tone. "We'll learn the motive when we find Mrs. Brown," said Tenson, who had made a note of Durwin's suggestion. "Many people think they have grievances against the rich, and we know that the late Sir Charles was a millionaire. He doubtless had enemies--dangerous enemies." "Dangerous!" The word recalled to Dan what Moon had said at the dinner-table when Lillian had playfully offered him a penny for his thoughts. "Sir Charles at dinner said something about dangerous people." "What did he say?" asked the Inspector and again opened his note-book. Dan reported the conversation, which was not very satisfactory as Moon had only spoken generally. Tenson noted down the few remarks, but did not appear to think them important. Durwin, however, was struck by what had been said. "Sir Charles asked me here to explain about a certain gang he believed was in existence," he remarked. "What's that, sir?" asked the Inspector alertly. "Did he tell you anything?" "Of course he didn't. How could he when he was dead when I arrived," retorted Durwin with a frown. "He simply said that he wished to see me in my official capacity about some gang, but gave me no details. Those were to be left until I called here. He preferred to see me here instead of at my office for reasons which he declared he would state when we met in this room." "Then you think that a gang----" "Mr. Inspector," interrupted Durwin, stiffly, "I have told you all that was said by the deceased. Whether the gang is dangerous, or what the members do, or where they are, I cannot say. Have you examined those windows?" he asked suddenly, pointing to three French-windows at the side of the room. "Yes," said Tenson promptly, "as soon as I entered the apartment I did so. They are all locked."