The tottering Lachaume mansion, with its attendant biscuit factory, had nothing to tempt a burglar. Who, then, was the killer of Leonard Lachaume? Maigret finds a sinister reason for the family's reluctance to talk.
Maigret comes into conflict with a defence lawyer intent on scoring points in the media at the police's expense. Mme Maigret has her own problems when she looks after a baby abandoned in a public park.
Louis Thouret lives in the suburbs of Paris. He is a henpecked, meek little man who leaves for and returns from work as regular as clockwork. Then one day he fails to return - and Maigret unravels a strange secret life.