Set in the Italian city of Malfi, John Webster’s tragedy tells the story of the Duchess, a young widow who falls in love with her steward, Antonio. However her scheming brothers, Duke Ferdinand and the Cardinal, want to stop the Duchess from marrying again as they are keen to eventually seize her fortune. The Duchess and Antonio marry in secret and have three children before they are discovered and brought to task by her brothers.
When the Duchess and Antonio attempt to run away, only Antonio and their eldest child manage to escape. The Duchess is betrayed by her servant Bosola, who was working as a spy for Ferdinand, and the brothers kill their sister and her younger children. Overcome with guilt and shame, Bosola declares that he will seek revenge for the Duchess. In a tragic chain of escalating violence, the Cardinal confesses his role in the murders to his mistress, Julia, but then murders her to keep her silence. Intent on seeking revenge, Bosola then mistakenly kills Antonio, believing him to be the Cardinal. Eventually Bosola murders the Cardinal but he and Ferdinand then kill each other in a brawl. As the play ends, the eldest son of Antonio and the Duchess takes his place as heir to the Malfi fortune.