The story follows Manda, a reformed criminal working as a carpenter, who falls in love with Marie, a woman associated with the "Apaches" gang. Their doomed romance triggers a violent rivalry between Manda and the gang leader, Felix Leca, eventually leading to Manda’s tragic execution.
The film is often summarized by the phrase " Tenderness and Violence ." Becker balances brutal gang warfare with scenes of quiet, intimate domesticity.
The role of Marie is widely considered the moral and visual center of the film:
Casque d'or is a key example of poetic realism, a movement that combines realistic social detail with heightened, lyrical aesthetics.