“Against that theory, however, there are two unanswerable arguments—firstly, the weapon used, which certainly was not one that would commend itself to the average British middle-class man on murder intent—a razor or knife would be more in his line; secondly, there is no doubt whatever that the murderer wore evening dress and an opera hat, a costume not likely to have been worn by any member of the Collins’ family, or their friends. We may, therefore, dismiss that theory also with equal certainty.” And he surveyed placidly the row of fine knots in his bit of string. “But then, according to you, who was the man in evening dress, and who but Harold Le Cheminant had any interest in getting rid of the claimant?” I asked at last. “Who, indeed?” he replied with a chuckle “who but the man who was as wax in the hands of that impostor.” “Whom do you mean?” I gasped. “Let us take things from the beginning,” he said, with ever-growing excitement, “and take the one thing which is absolutely beyond dispute, and that is the authenticity of the _papers_—the marriage certificate of Lucie Legrand, etc.—as against the authenticity of the _man_. Let us admit that the real Philip Le Cheminant was a refugee at St. Vincent, that he found out about his parentage and determined to go to England. He writes to his uncle, then sails for Europe, lands at Havre, and arrives in Paris.” “Why, Paris?” I asked. “Because you, like the police and like the public, have persistently shut your eyes to an event which, to my mind has bearing upon the whole of this mysterious case, and that is the original murder committed in Paris a year ago, also in a cab, also with a stiletto—which that time was _not_ found—in fact, in the self-same manner as this murder a week ago. “Well, that crime was never brought home to its perpetrator any more than this one will be. But my contention is, that the man who committed that murder a year ago, repeated this crime last week—that the man who was murdered in Paris was the real Philip Le Cheminant, whilst the man who was murdered in London was some friend to whom he had confided his story, and probably his papers, and who then hit upon the bold plan of assuming the personality of the Martinique creole, heir to an English peerage.” “But what in the world makes you imagine such a preposterous thing?” I gasped. “One tiny unanswerable fact,” he replied quietly. “William Collins, the impostor, when he came to London, called upon a solicitor, and deposited with him the valuable papers, _after that_ he obtained his interview with Lord Tremarn. Then mark what happens. Without any question, immediately after that interview, and, therefore, without even having seen the papers of identification, Lord Tremarn accepts the claimant as his newly-found nephew. “And why?