Back in Montreal after spending five years in Guatemala, Julie moves in with her elder sister, Jeanne, a chronic liar and woman of rather loose sexual morals. Disillusioned with love, Jeanne is nevertheless engaged to Noël. However, Jeanne and Noël lead separate lives, and only communicate by leaving each other messages posted on the fridge door. Everything suddenly becomes very complicated. Jeanne compels Julie to take up with Noël so she can have a fling with a passionate musician. Noel, meanwhile, looking to end his relationship with Helene, a married woman who is madly in love with him, sets Julie up with Michel - without Jeanne's knowledge.