A local advertisement announcing the date and location of a forthcoming murder has a small village buzzing with curiosity. Assuming it's a hoax, a crowd is nonetheless gathered at Letitia Blacklock's cottage at the appointed time when the lights go out and a gunman fires into the room. When the lights go up, Letitia is wounded and the mysterious gunman lies dead. Miss Marple, visiting an old friend in the village, can't resist joining the investigation.