In a provincial town, one night, Marc meets Sylvie when he has missed the train to return to Paris. They roam the streets until morning, talking about everything except themselves, in a rare chord, as if dancing. When Marc takes the first train, he arranges to meet Sylvie in Paris a few days later. So they don't know anything about each other, and it's more than a game, it's like that. Sylvie will go to this meeting, and Marc, unfortunately, not. He will look for her and find another, Sophie, without knowing that she is Sylvie's sister. Marc and Sylvie will meet again, their unparalleled agreement will not have disappeared, 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.