Zorg (Jean-Hugues Anglade), a 30-year-old handyman and unpublished writer, meets 19-year-old Betty (Béatrice Dalle), initiating an intense and passionate affair. After discovering Zorg's manuscript, Betty becomes fiercely devoted to his talent, typing out his novel and pushing for its publication. However, her violent temper tantrums and erratic behavior gradually escalate into severe psychological degradation. As they relocate across France, Zorg attempts to preserve her happiness despite fake pregnancies, criminal acts, and psychotic breaks. When Betty gouges out her eye and slips into a catatonic state at the hospital, Zorg makes a devastating final decision to mercy-kill her before returning to his writing.