It came in a flash to Tarling that the man who had thrown the bottle of vitriol at him, who had said he had kept it for years--was Sam Stay. Stay, with his scheme for blasting the woman who, he believed, had humiliated his beloved patron. And now for Milburgh, the last link in the chain. Tarling had arranged for the superintendent in charge of the Cannon Row Police Station to notify him if any news came through. The inspector's message did not arrive, and Tarling went down through Whitehall to hear the latest intelligence at first hand. That was to be precious little. As he was talking there arrived on the scene an agitated driver, the proprietor of a taxicab which had been lost. An ordinary case such as come the way of the London police almost every day. The cabman had taken a man and a woman to one of the West End theatres, and had been engaged to wait during the evening and pick them up when the performance was through. After setting down his fares, he had gone to a small eating-house for a bit of supper. When he came out the cab had disappeared. "I know who done it," he said vehemently, "and if I had him here, I'd...." "How do you know?" "He looked in at the coffee-shop while I was eating my bit of food." "What did he look like?" asked the station inspector. "He was a man with a white face," said the victim, "I could pick him out of a thousand. And what's more, he had a brand-new pair of boots on." Tarling had strolled away from the officer's desk whilst this conversation was in progress, but now he returned. "Did he speak at all?" he asked. "Yes, sir," said the cabman. "I happened to ask him if he was looking for anybody, and he said no, and then went on to talk a lot of rubbish about a man who had been the best friend any poor chap could have had. My seat happened to be nearest the door, that's how I got into conversation with him. I thought he was off his nut." "Yes, yes, go on," said Tarling impatiently. "What happened then?" "Well, he went out," said the cabman, "and presently I heard a cab being cranked up. I thought it was one of the other drivers--there were several cabs outside. The eating-house is a place which cabmen use, and I didn't take very much notice until I came out and found my cab gone and the old devil I'd left in charge in a public-house drinking beer with the money this fellow had given him." "Sounds like your man, sir," said the inspector, looking at Tarling. "That's Sam Stay all right," he said, "but it's news to me that he could drive a taxi." The inspector nodded. "Oh, I know Sam Stay all right, sir. We've had him in here two or three times. He used to be a taxi-driver--didn't you know that?" Tarling did not know that. He had intended looking up Sam's record that day, but something had occurred to put the matter out of his mind.