Isa (Elodie Bouchez), a drifter in her twenties, arrives in Lille, France, and takes a job in a dressmaking factory. A fellow-worker, Marie (Natacha Regnier), is looking after the flat of a woman and her daughter who were injured in an automobile accident. Shortly after moving in with Marie, Isa is fired. Then her new friend quits as well.

While Marie begins a relationship with Charly (Patrick Mercado), a bouncer at a local nightclub, Isa begins reading the diary of Sandrine, the teenager who lies in a coma. Soon she is adding her own entries into the diary. Then, in an act of empathy and compassion, Isa visits the girl at the hospital. Meanwhile, Marie ditches Charly in order to begin an affair with Chriss (Gregoire Colin), the owner of the nightclub.

In his first feature, director Erick Zonca draws out fine and nuanced performances from the two leads who shared the Best Actress prize at the 1998 Cannes Film Festival. This psychologically rich drama delineates the rift that eventually develops between the resiliently creative Isa and the self-destructive Marie. Zonca's lyrical cinema verite style magnifies the small tensions and flare-ups that can blow apart a friendship in the blink of an eye.