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 famous British houses and gardens with fifteen other people, arranged by Mr Rafiel prior to his death....