I stared, uncomprehendingly, and: “In what way does this throw light on the matter?” I asked. Durham--a very intelligent young officer--smiled significantly. “I begin to see light!” he declared. “The gentleman who made off just as I arrived on the scene probably had a private quarrel with the Chinaman and was otherwise not concerned in any way.” “I am disposed to agree with you,” I said guardedly. “Of course, you've no idea of his identity?” “I'm afraid not.” “We may find him,” mused the officer, glancing at me shrewdly, “by applying at the offices of the Planet Line, but I rather doubt it. Also I rather doubt if we'll look very far. He's saved us a lot of trouble, but”--peering about in the shadowy corners which abounded--“didn't I see somebody else lurking around here?” “I'm almost certain there was someone else!” I cried. “In fact, I could all but swear to it.” “H'm!” said the detective. “He's not here now. Might I trouble you to walk along to Limehouse Police Station for the ambulance? I'd better stay here.” I agreed at once, and started off. Thus a second time my plans were interrupted, for my expedition that night ultimately led me to Bow Street, whence, after certain formalities had been observed, I departed for my chambers, the mysterious pigtail in my pocket. Failing the presence of Durham, the pigtail must have been retained as evidence, but: “We shall know where to find it if it's wanted, Mr. Knox,” said the Yard man, “and I can trust you to look after your own property.” The clock of St. Paul's was chiming the hour of two when I locked the door of my chambers and prepared to turn in. The clangour of the final strokes yet vibrated through the night's silence when someone set my own door bell loudly ringing. With an exclamation of annoyance I shot back the bolts and threw open the door. A Chinaman stood outside upon the mat! IV HOW IT ALL ENDED “Me wishee see you,” said the apparition, smiling blandly; “me comee in?” “Come in, by all means,” I said without enthusiasm, and, switching on the light in my study, I admitted the Chinaman and stood facing him with an expression upon my face which I doubt not was the reverse of agreeable. My visitor, who wore a slop-shop suit, also wore a wide-brimmed bowler hat; now, the set bland smile still upon his yellow face, he removed the bowler and pointed significantly to his skull. His pigtail had been severed some three inches from the root! “You gotchee my pigtail,” he explained; “me callee get it--thank you.” “Thank you,” I said grimly. “But I must ask you to establish your claim rather more firmly.” “Yessir,” agreed the Chinaman.