The Duke, Lussurioso, the Duchess, Spurio, and Ambitioso and Supervacuo, the Duchess’s other two sons, enter. Junior Brother is brought in to stand trial for the rape of Antonio’s wife. Two judges are also present.
These characters represent the core of immorality at the Duke’s court. Spurio, Ambitioso, and Supervacuo’s names hint at “bastard,” “ambition” and “vacuous” respectively, giving the audience little hope of any redeeming features in their characters. The legal proceedings are a sham—the Duke who has final say over everything, which is another reason Vindice takes matters into his own hands.
The Duke apologizes to the Duchess for the fact that Junior Brother, her youngest son, must be punished for his crime. He says it’s important to do so to maintain their good reputation. One of the judges praises his wisdom; the Duke instructs the judge to “doom” Junior Brother.
Morality has been hollowed out from this court: the Duke has committed crimes as bad as Junior Brother, but thinks the latter should be punished only to protect the Duke’s own public image. His lack of leniency toward Junior Brother is also the start of the rift between the Duke and the Duchess, providing her with her own revenge motive.
The Duchess pleads on her knees for Junior Brother to be shown mercy. Lussurioso says that mercy is superficial and false, but Ambitioso also asks the Duke to “be soft and mild.” In an aside to audience, Spurio makes it clear that he hopes Junior Brother is sentenced to death.
Spurio pretty much resents everyone, but especially hates the Duke because, as a bastard born out of wedlock (and thus, essential, out of lust), he is denied any of the usual power and prestige that belong to the son of a Duke. Here the Duke is also shown to have the power to decide who lives and who dies—a power Vindice hopes to wrestle control of.
The judges quiz Junior Brother on why he committed the rape, to which he replies: “Why, flesh and blood, my lord. What should move man unto a woman else?” Lussurioso warns him not to be flippant with his answers.
Much to the Duchess’s dismay, the judge starts to pronounce the death sentence for Junior Brother. But before he can finish his statement, the Duke intervenes, instructing that the verdict will be deferred—and that Junior Brother should be merely imprisoned instead. Junior Brother is led away, and everybody else exits apart from the Duchess.
The Duke is an authoritarian power, deciding life and death on a whim. He could easily free Junior Brother and appease the Duchess, but he cares little for what she feels or thinks, further alienating her from him and demonstrating her own powerlessness.
The Duchess is furious with the Duke for not freeing Junior Brother. She vows to get her own back on him by “cuckolding” him—that is, having an affair. At this moment, Spurio re-enters the action. The Duchess expresses her attraction to Spurio, which so far has not been reciprocated.
The one shred of power that the Duchess does have is sex. Like the other women in the play, sex is the only thing that she—sometimes—has a say in. To be cuckolded was considered embarrassing for a man, especially for one in a position of power. The Duchess wants to double down on that humiliation by choosing the Duke’s own son—who himself exists only because of uncontrollable lust—as her partner.
Spurio greets the Duchess, who makes it obvious that she wants a kiss on her “lip” and not her “hand.” Spurio objects that this would be immoral as she is his father’s wife. The Duchess tries to persuade Spurio to think otherwise, pointing out that the Duke paid little attention to morals in fathering a bastard child and denying Spurio the usual rewards of being the son of a monarch.
Spurio becomes increasingly angry toward the Duke for his bastardy, and assents to have an illicit affair with the Duchess in order get “the vengeance that my birth was wrapped in.” They kiss, and the Duchess departs. Spurio says that despite his decision he hates the Duchess—as well as her sons, Lussurioso, and the Duke. He thinks his plan for revenge is logical: “For indeed a bastard by nature should make cuckolds, Because he is the son of a cuckold-maker.” He exits.
Already the audience sees three or four characters looking for revenge—the play lives up to his name. Like Vindice, Spurio is interested in the particular nature of his revenge. It seems especially appropriate to him that his revenge should involve acting on lust, because his very existence is due to similar behavior by the Duke. There are, then, parallels between Spurio’s conception and his vengeance. Spurio’s comment implies that he was conceived when the Duke had sex with a married woman, thus making the Duke a “cuckold-maker.”