Description
Jean-Paul, a writer and Marianne, his girlfriend of just over two years, are holidaying at a friend's villa. There is a tension in their relationship which excites Marianne: the film begins with a scene in which they are together beside the villa's swimming pool and she urges him to claw her back. He does as she asks, but then throws her into the pool and jumps in after her. In a later scene he takes a branch and uses it to lash her bare buttocks, playfully but with a force that increases as the scene cuts away.
Harry, an old friend and record producer who was Marianne's lover before Jean-Paul, arrives for a visit, surprising the couple by bringing along his 18-year-old daughter Penelope, whose existence they had not previously known about.
The four stay together and Harry draws Marianne back towards him as the days go by. Taunting Jean-Paul for having given up serious writing to work in advertising, Harry drinks a great deal and throws a surprise party while Jean-Paul, a recovering alcoholic, stays sober. Meanwhile, it becomes clear that Penelope neither likes nor respects her father, whom she has barely known while growing up. She and Jean-Paul become close and spend a day alone together by the sea.
That night, while the women are asleep, the two men finally confront each other. Harry falls into the pool and is too drunk to swim. Jean-Paul, who has also been drinking, at first stops him from climbing out of the water, then deliberately pushes Harry under and holds him down until he drowns. He covers up the crime by hiding Harry's wet clothes, making it look like an accident.
After the funeral, a policeman, Inspector Lévêque, visits the house more than once. He confides to Marianne his reasons for doubting the story of an accident. When she tells Jean-Paul, he confesses everything to her, and she goes to see the evidence that would have given him away. But when she does not give it to the police, the inquiry is dropped.
Marianne takes Penelope to the airport and sees her off as she returns to her mother. She and Jean-Paul are then about to leave the villa when she tells him that they will not go together. She calls for a taxi but he places his hand on the telephone, cutting off her call and silencing her. In the end, neither leaves that day, and in the film's final shot they stand side by side looking out the window at the swimming pool, and then embrace.
