He was equally unsuccessful in finding any link between Richard Pargent and any of the inhabitants of Praed Street. Their names were utterly unfamiliar to either of the sisters, and Mr. Pargent’s only connection with Praed Street appeared to be that he occasionally passed along it in a bus. Inspector Whyland was convinced that the same hand that had struck down Mr. Tovey, had killed Richard Pargent, and probably Mr. Colburn, though the receipt of the counter was the only link in the latter case. But what could be the motive for the murder of these three men, so entirely disconnected from one another? And, if one adopted the theory of a homicidal maniac, the difficulty was scarcely diminished. Homicidal maniacs either kill indiscriminately, or, as in the classic case of Jack the Ripper, they attack a certain class or type. Yet the receipt of the numbered counters implied some process of definite selection. Upon what possible grounds could such a selection be based?