In a villa on an island (St. Peter) a little out of season, inhabit Vanessa, a young widow, and stepdaughters Kikki and Vivi/. Vanessa had married their father above all because he was very rich. After her husband's death, she decided to keep the girls and also call Roberto, her former lover, now a professor with the aim of preparing the two girls to the maturity examination. Shortly after his arrival, he establishes an atmosphere heavy with half-empty Island villa that seems almost a luxury prison do understand immediately that the stepmother and stepdaughters will hate and despise each other.