The story revolves around the case of Miss Mary Sutherland, a woman with a substantial income from the interest on a fund set up for her. She is engaged to a quiet Londoner who has recently disappeared. Sherlock Holmes's detective powers are barely challenged as this turns out to be quite an elementary case for him, much as it puzzles Watson.
The fiancé, Mr. Hosmer Angel, is a peculiar character, rather quiet, and rather secretive about his life. Miss Sutherland only knows that he works in an office in Leadenhall Street, but ...view middle of the document...
A typewritten letter confirms his belief beyond doubt. Only one person could have gained by this: Mr. James Windibank. Holmes deduces "Angel" had "disappeared" by simply going out the other side of a four-wheeler cab.
After solving the mystery, Holmes chooses not to tell his client the solution, since "If I tell her she will not believe me. You may remember the old Persian saying, 'There is danger for him who taketh the tiger cub, and danger also for whoso snatches a delusion from a woman.' There is as much sense in Hafiz as in Horace, and as much knowledge of the world." In this, however, he can be accused of not fulfilling his professional duty for which he was paid – namely, to investigate the matter to which she set him, provide her with the results and let her decide what to do with them. Holmes does advise his client to forget "Mr. Angel"; Miss Sutherland refuses to take Holmes' advice and vows to remain faithful to "Angel" until he reappears – for at least ten years.
Holmes predicts Windibank will continue a career in crime and end up on the gallows.