The importance of finding the woman who had visited Seligmann was obvious, but it seemed impossible that a woman could have accomplished so savage a murder. Seligmann was a powerful man and would not prove an easy victim. Evidently the professor did not believe her solely responsible by the precise way in which he had asked the housemaid whether the woman was alone. In the afternoon I saw Mrs. Seligmann for a few moments. She told me that she and her husband had come to town together on Saturday. He had arranged to go to Hampstead after the opera, not to keep any particular appointment as far as she knew, and she had expected him to come on to Maidenhead afterward. She had gone back there after the opera. People constantly asked him to help them, but she could not conceive who her husband's visitor that night was. In answer to my question how her husband intended to get to Maidenhead, she said by taxi. He often did so after sending her off in the motor. When I left her I visited the nearest cab rank, and had confirmation of her statement. A driver told me he had taken Mr. Seligmann to Maidenhead once or twice. Seligmann would stop and tell him if he were on the rank at a certain time there would be a good job for him. He has also been to the house to call for him sometimes. On Saturday he had not seen him, nor could I find any other driver who had. Of course, he might have engaged a taxi elsewhere, but, as it was not his habit to do so, the presumption was that he had not intended to go to Maidenhead that night. Quarles had talked about criminals' mistakes, but I did not expect a murderer to be so careless as to hire a cab in the immediate neighborhood. I found, however, that three drivers had been engaged by solitary women that night. The description of the first woman did not correspond with the housemaid's, the second was not late enough to be Seligmann's visitor, but the third seemed worth attention. She had been driven to Chelsea, to a block of flats called River Mansions, and, interviewing the hall-porter later in the afternoon, I found that a Miss Wickham, who shared a flat there with a lady named Ross, had come home early on Sunday morning. She might be a singer, but the man thought she was an actress. "Is she in now?" I asked. "No; both ladies went away on Sunday morning. They often go either Saturday or Sunday, and come back some time on Monday. You might find them later in the evening. There's nothing wrong, is there?" he added, as though the respectability of the Mansions was a matter of concern to him. "Why should you think so?" "I'm old-fashioned, I suppose, and I expect to hear queer things about theatrical folk; besides, there's a friend of Miss Wickham's been here three times to-day, and he seemed worried at not finding her." "Oh, you mean Mr. Rowton," I said, and the porter fell into the trap. "No, I don't know him. This was Mr. Marsh--the Honorable Percival Marsh."