Vindice, still in disguise, enters with Hippolito, who is carrying a torch. Vindice is clearly excited about something, and Hippolito wants to know what. Vindice explains that the Duke has asked him—or “Piato” the pander—to find a woman for him. Vindice has arranged for the Duke to meet this woman tonight, away from the “eyes of the court,” at which point Vindice will kill the Duke and make him bear witness to Spurio and the Duchess’s affair.
Vindice is excited because he can sense that he is close to achieving his aim—not just revenge, but his particular brand of revenge. Vindice exploits the Duke’s lusty immorality, which allows him to orchestrate a situation in which the Duke is unguarded and vulnerable.
Hippolito is impressed by Vindice’s plan and asks where the woman is. Vindice tells him that this is the best part of the plan—the “lady” is Gloriana’s skull, dressed up. Vindice gleefully explains he will place poison on her lips—or where her lips would be—that will kill the Duke when he kisses her. The dying Duke will then die witnessing Spurio and the Duchess together—Vindice has arranged the Duke’s sexual liaison to take place at the same location as their illicit affair.
Vindice’s role as Piato, a dealer in lust, has allowed him to construct the type of revenge scenario that seems to him most appropriate for the Duke’s crime. Vindice’s plan shows that his obsession with revenge is more important to him than respecting the skull of Gloriana. On the other hand, his plan could be said to posthumously empower Gloriana, granting her the final, fatal act in the plan for vengeance.
Vindice and Hippolito hear the Duke approaching, and Vindice instructs his brother to hide with the skull. The Duke arrives with an entourage that he duly dismisses, instructing its members not to tell anyone at court of his location.
The Duke dismisses his entourage so that he can engage in his lustful behavior in private. But he also makes himself vulnerable by instructing the group to keep his location secret.
Vindice, still disguised as Piato, explains to the Duke that the woman he has found for him is a “country lady, a little bashful at first” with something of a “grave look” about her. He implores the Duke to go in strong for the first kiss and that she will then quickly lose her shyness. The Duke says that’s what he loves best anyway.
Vindice seems to revel in seeing his plan come to fruition, even making jokes to himself (“grave look”). He describes the “woman” as from the country because this explains her silence—she is intimidated by the Duke’s power and prestige. Of course, that’s all a lie. The Duke’s comment shows him to be similar to Lussurioso, in that, to them, the more virginal and pure a woman the more attractive she becomes.
Vindice tells Hippolito to back away with the torch and give him the skull. Vindice moves the skull towards the Duke, who plants it with a kiss. The Duke instantly realizes that something is terribly wrong and falls to the floor. Hippolito moves the torch back towards them.
The way in which Vindice poisons the Duke is darkly comic and also suggestive of the way lust is linked to death (by corrupting the “soul” or moral integrity of an individual). The Duke dies at the hands of his own lust—and in poisoned by the skull representative of death itself.
Vindice gleefully reveals to the Duke the identity of the skull (that is, Gloriana). Hippolito stamps on the Duke as the poison kicks in. Vindice then reveals his true identity to the Duke, and Hippolito charges the Duke with causing their father’s death too.
This is the moment that Vindice has been waiting for—the big reveal. It’s not enough for him to kill the Duke; he needs the Duke to know it’s him, and that he’s dying because of what the Duke did to Gloriana.
The Duke’s tongue starts to dissolve from the poison. Vindice isn’t finished with the Duke yet, however, telling him that before he dies he will become a “renowned, high and mighty cuckold” by witnessing his bastard son, Spurio, and the Duchess together. The Duke pleads with them not to force him to see that. Vindice and Hippolito place their daggers on the Duke, telling him he will get stabbed if he makes any noises.
What happens to the Duke tongue is symbolic of him having his sexual power taken away from him—tongues have sexual connotations, and in this case the Duke’s tongue also carries the suggestion of the biblical serpent from the book of Genesis. Forcing the Duke to witness Spurio and the Duchess will make him confront the fact that he presides over a kingdom of lust and, most importantly, intensifies his sense of powerlessness.
Spurio and the Duchess enter, kissing. The Duchess says, “there’s no pleasure sweet but it is sinful.” The Duke can’t help but make a sound, so Vindice stabs him to death. Exiting the stage, Vindice says to Hippolito that “the dukedom wants a head” and that they should “cut down” everyone that tries to claim it.
Lust, pleasure and immorality are linked together again. Vindice’s comment shows that his original desire for a revenge has morphed into a general death-wish, primarily for the others at court but, deep down, for himself too.