Agathe, an asthmatic child, lives with her mother Thérèse, a melancholic artist.

Alain and Virginie are getting married today, but Alain is on the verge of a nervous breakdown. The impending reunion of his divorced parents has plunged him into deep anxiety, only made worse by the shady schemes of his cousin and best man Edouard, who seems determined to get him involved. The groom now has only one ambition: to survive the happiest day of his life.