Returning home one day, Hercule Poirot finds a furious woman waiting outside his front door. She demands to know why he has sent her a letter accusing her of the murder of Barnabas Pandy, a man she has neither heard of nor ever met. Poirot has also never heard of Pandy, and he has certainly accused nobody of his murder. Shaken, he goes inside, only to find that he has a visitor waiting for him--a man who claims to have received a nearly identical...