In this short story, Agatha Christie presents the problem of unpunished crimes. During one meeting of the Tuesday Night Club. Henry Clithering, former commissioner of Scotland Yard, exposes an unsolved case. The mystery involves a murder with four suspects. It is only known that one of them worked in a terrorist organization bent on murdering the victim. Thanks to a series of clues, Miss Marple will be able to identify the true culprit and unravel the mystery.