Gilles Lantier, a young reporter on the AFP newspaper, is suffering from a nervous breakdown. Realising that neither his friend Jean nor his girlfriend Eloïse can help him, he decides to stay with his sister Odile, who lives near Limoges. At a party one evening he meets a wealthy bourgeois woman named Nathalie Sylvener. It is love at first sight, and on his return to Paris, Gilles tells Eloïse that he is now devotedly attached to another woman. Although Nathalie agrees to live with him in Paris, she rejects Gilles' offer of marriage. It is not long before the couple have settled into a routine and their passion begins to cool. Then Nathalie suddenly disappears from Gilles' life..