When a friend's brother-in-law is accused of murdering his daughter's lover, Maigret arrives in a small French town to help and is plunged into an atmosphere of animosity. He soon finds himself tangled up in a case that may ruin the very people whom he has come to aid and must face an old enemy - an ex-police officer nicknamed “Inspector Cadaver” - who seems to be doing everything in his power to obstruct Maigret's investigations.