After she attacks her mother for the third time, 15-year-old Manon is sent to an adolescent reform center far from home.

Manon learns to control her rage after being framed for a crime at the center; Mrs Barthélemy arranges for the girls to put on a puppet show at a local hall.

Manon is on her final warning but when her new educator Estelle finds a work placement at a garage, it seems things might finally be looking up.

Manon is now 20 years old and a qualified mechanic. She finds a job in a garage run by Mr. Hervé, but he refuses to employ her as a mechanic preferring to put her at reception. She is wooed by the deputy director, Jennifer, and strikes up a friendship with a young mechanic called Bruno. But her past resurfaces with the appearance of Lola, who was also at the detention centre.

Manon ends up falling for Bruno's gentle ways and kindness. At the same time, she is having a passionate secret affair with Jennifer, struggling with a job that she hates, and having to deal with the hostility of Mr Hervé after denouncing his dodgy dealings. As her old demons begin to rise to the surface again, Bruno suggests that she try to re-establish contact with her mother, but that fails.

Manon meets her father, but without telling him who she really is. The encounter really shakes her up. Monique, who is worried by her daughter's absence, goes looking for her at the garage and learns that she has been sacked.