Miss Marple receives a post card from the recently deceased Jason Rafiel, a millionaire whom she had met during a holiday on which she had encountered a murder, which asks her to look into an unspecified crime; if she succeeds in solving the crime, she will inherit £20,000. Rafiel has left her few clues. She begins by joining a tour of British famous houses and gardens, arranged by Mr Rafiel prior to his death. She is accompanied on the trip by fourteen other people. Elizabeth Temple is the retired headmistress of the school, who relates the story of Verity, who was engaged to Rafiel's ne'er-do-well son, Michael, but the marriage did not happen. Another member of the tour group, Miss Cooke, is a woman she had met briefly in St Mary Mead.