In this story, the protagonist, Horace Danby, is introduced as a seemingly good and honest citizen in his fifties. He is a successful locksmith with two employees and appears to be respectable. However, his secret life reveals that he is not entirely honest. Horace has a passion for rare and expensive books, which leads him to commit a burglary every year to fund his collection. He carefully plans each robbery, sells the stolen items, and buys the books he desires through an agent.
This year, Horace targets the house at Shotover Grange, where he knows there are valuable jewels in the safe. He has spent two weeks studying the house and its security measures. On the day of the planned robbery, the two servants who reside at the Grange are away at the movies. Horace enters the house, and while working on the safe, he is unexpectedly confronted by a young and pretty woman dressed in red.
The woman, claiming to be a family member, engages in conversation with Horace, who tries to charm and persuade her to let him go. She agrees, but on one condition: Horace must help her retrieve the jewels from the safe, as she has forgotten the combination. Desperate for his freedom, Horace accepts the deal and hands over the jewels once he has opened the safe. The woman promises to have the safe mended before her husband returns, and Horace leaves, feeling lucky to have escaped.
For two days, Horace keeps his promise not to commit any more burglaries. However, on the third day, he is arrested for the robbery at Shotover Grange. His fingerprints were found all over the room, as he had removed his gloves during the encounter with the woman. Horace tries to explain that the owner's wife had asked him to open the safe for her, but his story is dismissed as nonsense. The actual wife of the owner is revealed to be a grey-haired, sharp-tongued woman in her sixties, and not the charming young woman Horace had encountered.
In the end, Horace is imprisoned and becomes an assistant librarian. He often reflects on the clever young woman who tricked him, realizing that she was a fellow thief who had outsmarted him. The story concludes with Horace feeling bitter whenever he hears the phrase "honour among thieves," as his experience has proven otherwise.
