"But not in the Chinese language," replied Tarling, "and, Ling Chu, you speak no English." "I speak a little, master," said Ling Chu, "and I have heard these things in the streets." Tarling did not answer immediately, and the Chinaman waited. "Ling Chu," he said after awhile, "this man came to Shanghai whilst we were there, and there was trouble-trouble. Once he was thrown out from Wing Fu's tea-house, where he had been smoking opium. Also there was another trouble--do you remember?" The Chinaman looked him straight in the eyes. "I am forgetting," he said. "This white-face was a bad man. I am glad he is dead." "Humph!" said Tarling, and dismissed his retainer. Ling Chu was the cleverest of all his sleuths, a man who never lifted his nose from the trail once it was struck, and he had been the most loyal and faithful of Tarling's native trailers. But the detective never pretended that he understood Ling Chu's mind, or that he could pierce the veil which the native dropped between his own private thoughts and the curious foreigner. Even native criminals were baffled in their interpretation of Ling Chu's views, and many a man had gone to the scaffold puzzling the head, which was soon to be snicked from his body, over the method by which Ling Chu had detected his crime. Tarling went back to the table and picked up the newspaper, but had hardly begun to read when the telephone bell rang. He picked up the receiver and listened. To his amazement it was the voice of Cresswell, the Assistant Commissioner of Police, who had been instrumental in persuading Tarling to come to England. "Can you come round to the Yard immediately, Tarling?" said the voice. "I want to talk to you about this murder." "Surely," said Tarling. "I'll be with you in a few minutes." In five minutes he was at Scotland Yard and was ushered into the office of Assistant Commissioner Cresswell. The white-haired man who came across to meet him with a smile of pleasure in his eyes disclosed the object of the summons. "I'm going to bring you into this case, Tarling," he said. "It has certain aspects which seem outside the humdrum experience of our own people. It is not unusual, as you know," he said, as he motioned the other to a chair, "for Scotland Yard to engage outside help, particularly when we have a crime of this character to deal with. The facts you know," he went on, as he opened a thin folder. "These are the reports, which you can read at your leisure. Thornton Lyne was, to say the least, eccentric. His life was not a particularly wholesome one, and he had many undesirable acquaintances, amongst whom was a criminal and ex-convict who was only released from gaol a few days ago." "That's rather extraordinary," said Tarling, lifting his eyebrows. "What had he in common with the criminal?" Commissioner Cresswell shrugged his shoulders.