As against this, Tarling thought, it was notorious that criminals did foolish things. They took little or no account of the immediate consequences of their act, and a man like Milburgh, in his desperation, might in his very frenzy overlook the possibility of his crime coming to light through the very deed he had committed to cover himself up. He had reached the bottom of Edgware Road and was turning the corner of the street, looking across to the Marble Arch, when he heard a voice hail him and turning, saw a cab breaking violently to the edge of the pavement. It was Inspector Whiteside who jumped out. "I was just coming to see you," he said. "I thought your interview with the young lady would be longer. Just wait a moment, till I've paid the cabman--by-the-way, I saw your Chink servant and gather you sent him to the Yard on a spoof errand." When he returned, he met Tarling's eye and grinned sympathetically. "I know what's in your mind," he said frankly, "but really the Chief thinks it no more than an extraordinary coincidence. I suppose you made inquiries about your revolver?" Tarling nodded. "And can you discover how it came to be in the possession of----" he paused, "the murderer of Thornton Lyne?" "I have a theory, half-formed, it is true, but still a theory," said Tarling. "In fact, it's hardly so much a theory as an hypothesis." Whiteside grinned again. "This hair-splitting in the matter of logical terms never did mean much in my young life," he said, "but I take it you have a hunch." Without any more to-do, Tarling told the other of the discovery he had made in Ling Chu's box, the press cuttings, descriptive of the late Mr. Lyne's conduct in Shanghai and its tragic sequel. Whiteside listened in silence. "There may be something on that side," he said at last when Tarling had finished. "I've heard about your Ling Chu. He's a pretty good policeman, isn't he?" "The best in China," said Tarling promptly, "but I'm not going to pretend that I understand his mind. These are the facts. The revolver, or rather the pistol, was in my cupboard and the only person who could get at it was Ling Chu. There is the second and more important fact imputing motive, that Ling Chu had every reason to hate Thornton Lyne, the man who had indirectly been responsible for his sister's death. I have been thinking the matter over and I now recall that Ling Chu was unusually silent after he had seen Lyne. He has admitted to me that he has been to Lyne's Store and in fact has been pursuing inquiries there. We happened to be discussing the possibility of Miss Rider committing the murder and Ling Chu told me that Miss Rider could not drive a motor-car and when I questioned him as to how he knew this, he told me that he had made several inquiries at the Store. This I knew nothing about.