When the piercing eyes of this stranger rested upon Hi Wing Ho an expression which I shall never forget entered into them; an expression coldly murderous. As for the Chinaman, he literally crumpled up. “You rat!” roared the stranger. Taking one long stride he stooped upon the Chinaman, seized him by the back of the neck as a terrier might seize a rat, and lifted him to his feet. “The mystery of the pigtail, Mr. Knox,” said the detective, “is solved at last.” “Have ye got it?” demanded the Scotsman, turning to me, but without releasing his hold upon the neck of Hi Wing Ho. I took the pigtail from my pocket and dangled it before his eyes. “Suppose you come into my study,” I said, “and explain matters.” We entered the room which had been the scene of so many singular happenings. The detective and I seated ourselves, but the Scotsman, holding the Chinaman by the neck as though he had been some inanimate bundle, stood just within the doorway, one of the most gigantic specimens of manhood I had ever set eyes upon. “You do the talking, sir,” he directed the detective; “ye have all the facts.” While Durham talked, then, we all listened--excepting the Chinaman, who was past taking an intelligent interest in anything, and who, to judge from his starting eyes, was being slowly strangled. “The gentleman,” said Durham--“Mr. Nicholson--arrived two days ago from the East. He is a buyer for a big firm of diamond merchants, and some weeks ago a valuable diamond was stolen from him------” “By this!” interrupted the Scotsman, shaking the wretched Hi Wing Ho terrier fashion. “By Hi Wing Ho,” explained the detective, “whom you see before you. The theft was a very ingenious one, and the man succeeded in getting away with his haul. He tried to dispose of the diamond to a certain Isaac Cohenberg, a Singapore moneylender; but Isaac Cohenberg was the bigger crook of the two. Hi Wing Ho only escaped from the establishment of Cohenberg by dint of sandbagging the moneylender, and quitted the town by a boat which left the same night. On the voyage he was indiscreet enough to take the diamond from its hiding-place and surreptitiously to examine it. Another member of the Chinese crew, one Li Ping--otherwise Ah Fu, the accredited agent of old Huang Chow!--was secretly watching our friend, and, knowing that he possessed this valuable jewel, he also learned where he kept it hidden. At Suez Ah Fu attacked Hi Wing Ho and secured possession of the diamond. It was to secure possession of the diamond that Ah Fu had gone out East. I don't doubt it. He employed Hi Wing Ho--and Hi Wing Ho tried to double on him!