Staying with his old friend Judge Chabot in Fontenay, Maigret learns of two murders that have stirred up old grievances in the town and is, very reluctantly, drawn into investigating.
A young woman in evening dress is found dumped in the street having been murdered. Maigret tries to learn about her short life in the hope of finding her killer.
Off duty, Lapointe is on his way home late at night. Hearing a gunshot and a scream coming from the house of a wealthy and influential family he rushes to investigate.
Madame Maigret is delighted to get her husband away from work for a few days by the sea in Normandy but soon realizes that the Chief Inspector is unofficially on a case of murder among the crew of a trawler.
Just as he is wrapping up a smuggling case in Honfleur, Maigret is told that a local judge has a dead body in his house and is planning to dispose of it in the harbour that night.
Murder in one of the best hotels in Paris leads Maigret to Nice, Monaco, and Switzerland as he seeks a killer in the world of the jet-setting super-rich.