Asked to help a friend's brother-in-law who is accused of murdering the lover of his daughter, Maigret arrives in a small French town and finds himself 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 help. He also has to deal with an old enemy - an ex-police officer nicknamed 'Inspector Cadaver' - who seems to be doing everything in his power to obstruct Maigret's investigations.