“The number of the house is forty,” Ford told him; “the name on the door-plate, Dr. Prothero. Find out everything you can about him without letting any one catch you at it. Better begin at the nearest chemist's. Say you are on the verge of a nervous breakdown, and ask the man to mix you a sedative, and recommend a physician. Show him Prothero's name and address on a piece of paper, and say Prothero has been recommended to you as a specialist on nervous troubles. Ask what he thinks of him. Get him to talk. Then visit the trades-people and the public-houses in the neighborhood, and say you are from some West End shop where Prothero, wants to open an account. They may talk, especially if his credit is bad. And, if you find out enough about him to give me a working basis, I'll try to get into the house to-night. Meanwhile, I'm going to make another quick search of this hotel for Pearsall. I'm not satisfied he has not been here. For why should Miss Dale, with all the hotels in London to choose from, have named this particular one, unless she had good reason for it? Now, go, and meet me in an hour in Sowell Street.” Cuthbert was at the door when he remembered he had brought with him from the office Ford's mail and cablegrams. Among the latter was the one for which Ford had asked. “Wait,” he commanded. “This is about the girl. You had better know what it says.” The cable read: “Girl orphan, Dalesville named after her family, for three generations mill-owners, father died four years ago, Pearsall brother-in-law until she is twenty-one, which will be in three months. Girl well known, extremely popular, lived Dalesville until last year, when went abroad with uncle, since then reports of melancholia and nervous prostration, before that health excellent--no signs insanity--none in family. Be careful how handle Pearsall, was doctor, gave up practice to look after estate, is prominent in local business and church circles, best reputation, beware libel.” For the benefit of Cuthbert, Ford had been reading the cable aloud. The last paragraph seemed especially to interest him, and he read it twice, the second time slowly, and emphasizing the word “doctor.” “A doctor!” he repeated. “Do you see where that leads us? It may explain several things. The girl was in good health until went abroad with her uncle, and he is a medical man.” The eyes of Cuthbert grew wide with excitement. “You mean poison!” he whispered. “Slow poison!”