Till Death Do Us Part
John Dickson Carr
 Dick Markham is engaged to Lesley, but he doesn't really know much about her. When they attend a cricket match in the little English village of Six Ashes, they stop at the associated fete and Lesley insists on seeing the fortune teller. She is apparently unaware that the fortune teller is being played by Sir Harvey Gilman, the Home Office pathologist and expert on crime. After her visit, Dick visits Sir Harvey, who is apparently about to tell him something unpleasant about his fiancee when he is shot—accidentally, by all reports, and certainly non-fatally—by Lesley. Later that night, Sir Harvey tells Dick that Lesley is really a murderess who has poisoned three husbands using a mysterious method of death that seemingly must be suicide, whereby the victim injects himself with hydrocyanic acid. Later that night, Sir Harvey dies in a locked and sealed room, seemingly after having injected himself with hydrocyanic acid. Gideon Fell is called in to assist the police investigation. It is soon discovered that "Sir Harvey" is actually a confidence man named Sam De Villa, and his revelations about Lesley are untrue, but this doesn't answer other important questions. What is the significance of a box of drawing pins found scattered beside the corpse? Who fired a rifle into the murder room in the early hours of the next morning? It takes another murder before Dr. Fell reveals the identity of the murderer and the method by which the room was locked. it:Un colpo di fucile