Maigret, in retirement on the banks of the Loire at Meung-sur-Loire, receives a letter from a young girl, Berthe who claims her life was threatened, and who says she was the niece of a man who was for a long time his colleague in the Police Judiciaire, and who died by his side shortly before Maigret's retirement, Lucas. She asks him to meet her in the Café de Madrid, where she explains that her ex-boyfriend, Albert Marcinelle, had fallen in with bad company, taken part in a robbery, and killed a policeman. He's now sending her letters, which she shows him, asking her to join him and threatening dire consequences if she doesn't. Berthe is a dressmaker in the Rue Caulaincourt, and Maigret takes a room in the hotel opposite.
He meets Berthe's brother, Louis the Kid, and his his nephew, Jérôme Lacroix, who he'd gotten into the Police Judiciaire, interrogate him. Then Berthe is attacked in her apartment, knocked over the head, and her bleeding assailant fled the scene. Maigret understands, and goes to say goodbye, leaving the problem to his nephew. Albert had been hiding next to her room, innocent, but fearing the other members of the gang, who thought he had the money. One of them came to search, knocking out Berthe, but Albert had rushed out and stabbed him. She'd called in Maigret more to protect Albert and keep tabs on developments than anything else. Maigret wishes her luck, saying he wouldn't be surprised to hear that a new dressmaker had opened up in Brussels some day.
This report prepared by Dana Samson