But Ayscough knew one useful thing--he had memorized the letters and numbers of the taxi-cab in which Yada had sped by him and Mirandolet, L.C. 2571--he had kept repeating that over and over. Now he took out his note-book and jotted it down--and that done he set off to the police-station, intent first of all on getting in touch with New Scotland Yard by means of the telephone. Ayscough, like most men of his calling in London, had a considerable amount of general knowledge of things and affairs, and he summoned it to his aid in this instance. He knew that if the Japanese really had become possessed of the orange and yellow diamond (of which supposition, in spite of Mirandolet's positive convictions, he was very sceptical) he would most certainly make for escape. He would be off to the Continent, hot foot. Now, Ayscough had a good acquaintance with the Continental train services--some hours must elapse before Yada could possibly get a train for Dover, or Folkstone, or Newhaven, or the shortest way across, or to any other ports such as Harwich or Southampton, by a longer route. Obviously, the first thing to do was to have the stations at Victoria, and Charing Cross, and Holborn Viaduct, and London Bridge carefully watched for Yada. And for two weary hours in the middle of the night he was continuously at work on the telephone, giving instructions and descriptions, and making arrangements to spread a net out of which the supposed fugitive could not escape. And when all that was at last satisfactorily arranged, Ayscough was conscious that it might be for nothing. He might be on a wrong track altogether--due to the suspicions and assertions of that queer man, Mirandolet. There might be some mystery--in Ayscough's opinion there always was mystery wherever Chinese or Japanese or Hindus were concerned. Yada might have some good reason for wishing to see Chen Li's dead body, and have taken advantage of the detective's card to visit it. This extraordinary conduct might be explained. But meanwhile Ayscough could not afford to neglect a chance, and tired as he was, he set out to find the driver of the taxicab whose number he had carefully set down in his notebook. There was little difficulty in this stage of the proceedings; it was merely a question of time, of visiting a central office and finding the man's name and address. By six o'clock in the morning Ayscough was at a small house in a shabby street in Kentish Town, interviewing a woman who had just risen to light her fire, and was surlily averse to calling up a husband, who, she said, had not been in bed until nearly four. She was not any more pleased when Ayscough informed her of his professional status--but the man was fetched down.