Frédéric, 18, leads a directionless life when he is arrested for drug use. Sent to prison, he meets two older inmates, Louis-Guy and Damien, an experienced robber and a seasoned con artist. Fascinated by their confidence, Frédéric falls under their influence; prison becomes a kind of "school" where he discovers the world of crime. After his release, he briefly tries to rebuild his life: he moves back in with his father, finds a modest job, and maintains a stable relationship. But he remains fragile and still drawn to the excitement and sense of belonging his former cellmates offered him. When they contact him again, he slips back into crime and takes part in a first robbery. When his girlfriend discovers the stolen money, she leaves him, but Frédéric only sinks deeper. A second, more ambitious robbery targets a bank. The trio manages to break into the vaults and escape with a large sum before being surprised by the police. They flee in confusion. But the investigation catches up with them: marked bills are found at Frédéric's father's home, putting his father at risk of being charged with handling stolen goods. Forced to choose between protecting his accomplices or his innocent father, Frédéric ultimately confesses everything. He is sentenced to six years in prison.