In the 1960s in Normandy, Mina, Georges' beautiful and sensible wife, seeks to escape from her routine life by going to the cinema with Tommy, their fifteen-year-old boy. After a screening of West Side Story, Matthias, a man they are sitting next to, invites them for a drink at a dance hall. At the same time, Georges finds a job at a building site and is compelled to stay away from home the whole week long. The growing passion between Mina and Matthias is as painful for Tommy as for Georges. He finally accepts Mina's departure, as he hopes that this love affair will not last long ...