Édouard and Félix, two inseparable friends, live off the times and do odd jobs, sharing a tiny apartment in Montmartre with Laurence, Félix's sister, a model in a fashion house who alone supports the trio.

Young provincial Charles arrives in Paris to stay with his cousin Paul while studying law. Paul is a decadent, bohemian pleasure-seeker who shows the meek, diligent Charles the thrills of city life. When Charles falls for Florence, one of Paul's acquaintances, relationships begin to shift.

Nicole Montigny leaves her husband, surgeon Paul, to live with her lover in Canada. Anna, her husband's assistant, thinks she can take advantage of the situation to console the man she loves. She convinces Nicole to fake an accident. However, Paul starts seeing his wife's twin sister, Mireille. Anna, mad with jealousy, brings Nicole back and tries to break up the new couple by blackmail. Nicole decides to eliminate Anna.