Of all the problems which have been submitted to my friend, Mr. Sherlock Holmes, for solution during the years of our intimacy, there were only two which I was the means of introducing to his notice-that of Mr. Hatherley\'s thumb, and that of Colonel Warburton\'s madness. Of these the latter may have afforded a finer field for an acute and original observer, but the other was so strange in its inception and so dramatic in its details that it may be the more worthy of being placed upon record, even if it gave my friend fewer openings for those deductive methods of reasoning by which he achieved such remarkable results. The story has, I believe, been told more than once in the newspapers, but, like all such narratives, its effect is much less striking when set forth en bloc in a single half-column of print than when the facts slowly evolve before your own eyes, and the mystery clears gradually away as each new discovery furnishes a step which leads on to the complete truth. At the time the circumstances made a deep impression upon me, and the lapse of two years has hardly served to weaken the effect. It was in the summer of \'89, not long after my marriage, that the events occurred which I am now about to summarise. I had returned to civil practice and had finally abandoned Holmes in his Baker Street rooms, although I continually visited him and occasionally even persuaded him to forgo his Bohemian habits so far as to come and visit us. My practice had steadily increased, and as I happened to live at no very great distance from Paddington Station, I got a few patients from among the officials. One of these, whom I had cured of a painful and lingering disease, was never weary of advertising my virtues and of endeavouring to send me on every sufferer over whom he might have any influence. One morning, at a little before seven o\'clock, I was awakened by the maid tapping at the door to announce that two men had come from Paddington and were waiting in the consulting-room. I dressed hurriedly, for I knew by experience that railway cases were seldom trivial, and hastened downstairs. As I descended, my old ally, the guard, came out of the room and closed the door tightly behind him.