In a provincial town, one night, Marc meets Sylvie after missing the train back to Paris. They wander the streets until morning, talking about everything except themselves, in a rare harmony, as if dancing. When Marc catches the first train, he makes a date with Sylvie in Paris, a few days later. They know nothing about each other, and it’s much more than a game; that’s just how it is. Sylvie goes to the meeting place, but Marc, by misfortune, does not. He searches for her and finds another, Sophie, without knowing she is Sylvie's sister. Marc and Sylvie eventually reunite; their unparalleled harmony hasn't faded, but it’s too late...

A tax inspector (Benoît Poelvoorde), his new bride (Chiara Mastroianni) and her sister (Charlotte Gainsbourg) become entwined in a love triangle.