Neither the man nor the woman had carried any baggage. The chauffeur had gathered that the person who was ill was a relative of both of them, and that the nurse’s rather bewildered manner was due to her anxiety and the suddenness of the call. That was all Nick could learn from him, and an immediate visit to the Yellow Anchor Line’s pier was imperative. There it was learned that a man and woman answering the description given had been noticed in the crowd of people who had come to bid good-by to relatives and friends. One man was sure he had seen them enter a taxi which had just dropped its passengers. When interrogated further, he gave it as his impression that the taxi was a red-and-black machine. He naturally did not notice its number, and no one else could be found who had seen even that much. A wireless inquiry brought a prompt reply from the _Laurentian_, to the effect that no couple of that description were on board, or had been seen on the vessel the night before. It was clear that Grantley had made a false trail, for the purpose of throwing off his pursuers. It had been a characteristic move, and no more than Nick had expected. The detective turned his attention to the taxi clew. Red and black were the distinctive colors of the Flanders-Jackson Taxicab Company’s machines. Consequently, the main garage of that concern was next visited. Luckily, the man at the pier had been right. One of the company’s taxis had been at the Yellow Anchor Line pier the previous night, and had picked up a couple of new passengers there, after having been dismissed by those who had originally engaged it. Nick obtained the name and address of the chauffeur, who was off duty until night. He was not at home when the detective called, but, after a vexatious delay, he was eventually located. A tip loosened his tongue. “I remember them well, sir,” he declared. “The man looked like a doctor, I thought, and, if I’m not mistaken, the woman had on a nurse’s uniform under her long coat. I couldn’t see her face, though, on account of the heavy veil she wore. She acted queer--sick or something. The fellow told me, when they got in, to drive them to the Wentworth-Belding, but when I got up to Fourteenth Street, he said to take them to the Metropolitan Building. I did, and they got out. That’s all I know about it. I drove them to the Madison Square side, and they had gone into the building before I started away, but that’s the last I saw of them.” “Well, we’ve traced them one step farther, Chick,” Nick remarked to his first assistant as they left, “but we haven’t tracked them down, by a long shot. Grantley doubtless went through the Metropolitan Building to Fourth Avenue. There he either took the subway, hailed another taxi, or--hold on, though! Maybe there’s something in that! I wonder----” “Now, what?” Chick asked eagerly. “You remember Doctor Chester, one of the six young physicians who was mixed up with Grantley in that vivisection case?”