Lucrezia and her brother Cerase lead a life of perverse love affairs. One day, Lucrezia meets a young man and falls in love with him. Cesare kills her lover. Lucrezia is horrified. To distract her, her brother throws a banquet, during which assassins hired by Lucrezia burst into the hall. Standing over her dying brother, Lucrezia laughs – she has had her revenge! But she has forgotten Cesare's treachery: the wine she drank was poisoned.