The day she turns 40, Marguerite Flora, a successful rep for a nuclear power company, begins receiving letters she'd sent to herself at age seven. The letters tell her what to do if her life hasn't turned out the way she thought it should, when she was living in poverty with her mother and brother in a small village in southern France. She decides to go back to her birthplace to get the lawyer to stop the letters, but also to visit her childhood sweetheart and her long-forgotten brother, in order to find peace within herself.

During the war of Indochina, Claire tries to maintain the link between her parents.