Paul wants to spend a romantic holiday with his girlfriend Marianne on an Italian island. But just a few days after their arrival, their time together is disrupted by a visit from their old friend Harry and his daughter Penelope. Paul quickly finds himself attracted to Penelope, while at the same time Harry and Marianne are drawn to each other once again. Gradually, all four of them are caught up in a whirlwind of jealousy, passion and obsession.