As the story opens, Jane Marple is paying a visit to her old friend Ruth Van Rydock. Miss Marple, Ruth, and Ruth's sister Carrie Louise were all friends together at the same school in Italy when they were girls. Ruth is worried that something is very wrong at Stonygates, the Victorian mansion where Carrie Louise lives with her husband Lewis Serrocold. She can't explain any real reason for these worries, but she fears that Carrie Louise may be in danger of some kind. Ruth asks Miss Marple to visit her and find out what is going on.