Simon is a writer lacking inspiration. His editor has however fixed a deadline for the delivery of his next manuscript. When his friend, Judith, talks to him about the marital and sexual problems of her friends Ursula and Romain, he decides to take advantage of this situation, hoping to find an interesting subject for his novel. Ursula and Romain invite him to a small party at their home. There, the writer offers them a book listing many tricks to solve their small problems. The couple soon check the validity of these tips and begins to regain a satisfying sex life .