While visiting her American school friend Ruth Van Rydock in London, Miss Marple learns that Ruth is seriously concerned for her sister Carrie Louise. She asks Miss Marple to visit Carrie Louise at Stonygates, her home in England. Miss Marple agrees to the visit. She is impressed by the size of the Victorian mansion, which now has a separate building for delinquent boys, the cause which engages Carrie Louise and her third husband, Lewis Serrocold. Carrie Louise has her family living with her, as her granddaughter Gina has brought her American husband Walter to England to meet her family. Daughter Mildred Strete moved back home after she was widowed. Stepsons Stephen and Alexis Restarick, now grown, are frequent visitors and are present during Miss Marple's visit. One of the first people Miss Marple encounters is Edgar Lawson, a young man acting as a secretary to Serrocold; Lawson shows clear signs of paranoid schizophrenia, but these are largely ignored. =