The murder of a bandit gives a policeman the opportunity to unmask the activities of a spy.

Thanks to the complicity of his friend Laura, Jo, sentenced to 20 years in prison, escapes from the central prison. Hiding in an old disused mill, Jo sends his young friend to a certain Freddy, gangster and nightclub owner in Pigalle, who owes his freedom to Jo's silence. But Freddy sends two of his henchmen to the mill where Jo is hiding, to kill her.

At the Opera of Toulon, the cast and crew hoping to put on a Satanism / human sacrifice-themed ballet entitled “La malédiction de Belphégor” soon find their numbers dwindling.

At the Opera of Toulon, the cast and crew hoping to put on a Satanism / human sacrifice-themed ballet entitled “La malédiction de Belphégor” soon find their numbers dwindling.

At the Opera of Toulon, the cast and crew hoping to put on a Satanism / human sacrifice-themed ballet entitled “La malédiction de Belphégor” soon find their numbers dwindling.

Maroîs, the fairground bon vivant, spends most of his time around a bottle of wine, in the company of his friend Michaux, with whom he was once a sailor. He neglects his wife Monique, a pretty girl much younger than himself. Suffering from this indifference, she seeks imperfect and fleeting consolation, first from Michel, their friend's son, then from Jean-Louis, a young mechanic who has helped out with Maroîs' truck and won his trusting friendship. Michel, jealous, tells the showman of his misfortune. He leaves to kill his wife's lover. The latter, wishing to separate the antagonists, seriously burns herself by knocking over an autogenous welding block, which explodes. Taken to hospital, she asks for and receives her husband's forgiveness.

Maroîs, the fairground bon vivant, spends most of his time around a bottle of wine, in the company of his friend Michaux, with whom he was once a sailor. He neglects his wife Monique, a pretty girl much younger than himself. Suffering from this indifference, she seeks imperfect and fleeting consolation, first from Michel, their friend's son, then from Jean-Louis, a young mechanic who has helped out with Maroîs' truck and won his trusting friendship. Michel, jealous, tells the showman of his misfortune. He leaves to kill his wife's lover. The latter, wishing to separate the antagonists, seriously burns herself by knocking over an autogenous welding block, which explodes. Taken to hospital, she asks for and receives her husband's forgiveness.

"Professor Marian died under mysterious circumstances."