Fourteen years after her mother, Caroline Crale, was hanged for the murder of her artist father Amyas Crale, Lucy Crale asks Hercule Poirot to investigate her father's death. She is convinced that her mother was innocent, but she is willing to accept the truth, whatever it may be. Poirot visited the five people present when the murder took place in turn, including Amyas's best friend Philip Blake, who was visiting the Crales when Amyas was murdered; Meredith, Philip's brother, from whom Caroline allegedly stole the poison she drew to kill her husband; Elsa Greer, who was sitting for a portrait and with whom Amyas was supposedly in love; Caroline's half-sister Angela, who despised Amyas but believed her sister was innocent; and Miss Williams, the governess. Having heard the story from five different perspectives, Poirot rallies them all to identify the murderer.