Jean Gabin plays Monsieur Maroilleur, the owner of a farm and runs it with his sons-in-law, while his daughters take care of the house and kitchen. He is furious when his grandson Henri (Marc Porel - who played one of Gabin's sons in The Sicilian Clan) uses the farm to hide heroin until his friends, a gang of drug smugglers, pick the packet up. Maroilleur destroys the packet and hides Henri in a basement so that the gang cannot harm him. The gang terrorizes the farm, kill 27 of his cows (great scene!); but Maroilleur fights back and all 5 members of the gang, who know Henri, die. The police who notice strange things happened in the farm try to investigate.
Jean Gabin is very convincing as a dictatorial farmer. An old man fights a gang of drug smugglers, if it wasn't Gabin, I know I would not believe anything. He chooses to fight to protect the family's honour, so that his grandson doesn't go to jail. "If anyone here goes to jail, it's me." says Maroilleur to the inspector. The police ransack the farm and when they finally find Henri in the basement, Henri's testimony made me laugh. It's so unexpected, yet quite believable, that the judge believes his story and let the old Maroilleur go home.