Blanche has recently moved to Cergy-Pontoise to work at the town hall. During a lunch break she meets the vivacious and immediately likable Léa. Although she is not fond of sports, Léa agrees to go swimming with Blanche at the local pool. There they meet Alexandre, one of Léa's acquaintances, along with Adrienne, his current girlfriend. Blanche finds herself under the spell of the young engineer. The holidays arrive, Léa leaves while Blanche stays on. By chance, Blanche bumps into Alexandre in the street. She clumsily tries to make a pass at him. Soon she's also bumping into Fabien, Léa's boyfriend.