A wealthy woman holds a party at her Devon estate for family and friends. When a solicitor and the hostess herself are both murdered, Miss Marple tries to find a clever killer with a devious plan.
Miss Marple is visiting an old school friend, Lady Camilla Tressilian, along with an eclectic group: Neville Strange and his wife Kay, his former wife Audrey and her childhood friend and cousin Thomas Royde, Ted Latimer (who is something of a gigolo and very attracted to Kay Strange) and finally Freddie Treves, a retired solicitor.
When Treves is found dead the day after a dinner party at Lady Tressilian's home and Lady Tressilian herself is found bludgeoned to death a short time later, Miss Marple must sort through the complex set of relationships among all the players, and determine what role the tale of a child's crime may have had to play in the deaths.