Clément, a cynical and joyfully melancholy film extra, is madly in love with Mona, who works at a sandwich stand in the Gare du Nord in Paris. But Mona has a secret, which makes her vague and evanescent. When Clément despairs of ever winning her over, his only and best friend, Abel, comes to his rescue. Together, they set out on an adventure of romantic conquest. But the number three is one too many for two.