The Duchess of Malfi is divided into five acts, each comprising several scenes. In the three scenes of act 1, the major characters and conflicts are introduced. The setting is the Italian city of Amalfi in the sixteenth century, in the audience chamber or ‘‘presence’’ of the widowed Duchess. Antonio, the Duchess's steward, talks with his friend Delio as they observe the others who passthrough the chamber. The first to enter are the Cardinal and Bosola. Although Bosola has recently been released after serving seven years for a murder he committed at the behest of the Cardinal, the Cardinal is cold to him and will not acknowledge his debt.
Ferdinand, the Duke of Calabria, enters with his entourage. Ferdinand learns that Antonio has proven himself the best at a knightly competition,and he congratulates Antonio for his prowess and for his eloquent speech. When the Cardinal reenters with the Duchess, Antonio gives Delio his impression of the three siblings: the Cardinal is jealous and vengeful, Ferdinand is ‘‘perverse and turbulent,’’ and the Duchess is sweet and noble. Ferdinand asks the Duchess to accept Bosola as a servant, and she agrees; in fact, the brothers have hiredBosola to spy on the Duchess.
The two brothers warn the Duchess not to remarry, and she promises that she will not. However, as soon as they leave her chamber, she summons Antonio and the two perform a private marriage ceremony, with the Duchess's trusted servant Cariola as witness.
The second act, which has five scenes, begins several months later as the Duchess is about to give birth toa child. Her marriage to Antonio is still secret, and she has concealed her pregnancy by wearing loose clothing. Bosola, however, suspects that she is pregnant and tries to trap her by giving her a present of apricots. When she devours them hungrily and then vomits, he has confirmation of the pregnancy but does not reveal what he knows. The incident sends the Duchess into labor, and she is rushedto her chamber.
To avoid suspicion that the Duchess is giving birth, a ruse is invented: it is announced that jewels have been stolen, and everyone must stay in his or her room while a search is conducted. The Duchess delivers a healthy son, and when Cariola tells Antonio the good news, he prepares a set of calculations based on astrology to determine the baby's future. Meanwhile, Bosola sneaksout to the courtyard beneath the Duchess's window and hears her crying out. Antonio finds him there, and they argue about Bosola having left his room. As he leaves Bosola, Antonio accidentally drops the paper on which he has written his astrological notes, and Bosola retrieves it, discovering that a baby has been born to the Duchess—a baby who will have a short life. Bosola knows that Antonio isin on the secret but does not consider that a man of Antonio's social class could be the father.
In Rome, the Cardinal meets in his chamber with Julia, his mistress. Delio arrives and propositions Julia, but she refuses him. In another part of the Cardinal's palace, Ferdinand has received a letter from Bosola, telling him of the baby's birth. The Cardinal and Ferdinand discuss their sister'sbetrayal, and Ferdinand's rage takes him to the brink of insanity.
Several years pass before the five scenes in act 3 take place. The Duchess has given birth to two more children, but her marriage is still a secret, and Bosola still has not discovered the identity of the father. Ferdinand, finally stirred to action, arrives at the Duchess's palace to confront her. To play an affectionate jokeon her, Antonio and Cariola step out of the room while the Duchess is talking to herself in the mirror, and Ferdinand comes into the room at the same moment. He accuses her of shaming the family with her promiscuity, and although she tells him that she is married, he vows never to look at her again.
Afraid of Ferdinand's anger, the Duchess sends Antonio to safety by pretending that he has stolen...