In the Cardinal’s palace, the Cardinal tells Pescara, Malateste, Roderigo, and Grisolan to leave the sick Ferdinand alone that night. The Cardinal emphasizes that they must promise not to come into the Cardinal’s room, even if someone calls for them, and he says that he might even test them and pretend to be in danger. They swear they will not come. After they exit, the Cardinal says to himself that he was taking precautions to ensure privacy to deal with Julia’s body. He reveals that his conscience is plaguing him, and that he would pray if the devil weren’t stopping him. Meanwhile, Bosola enters, unseen by the Cardinal. Bosola then overhears the Cardinal say that when Bosola has fulfilled his service, he will be killed.
In order to prevent his courtiers from finding out about the murders, the Cardinal orders them not to come to his room no matter what. Later, this will prove a fatal mistake. More and more we see that the Cardinal, too, is being plagued by guilt, to the point where, even though he is a Cardinal, he feels like the devil is preventing him from praying. The Cardinal makes the other key mistake in revealing to Bosola that he plans to have Bosola killed. This is another break from the usually calculating, careful political mastermind presented at the play’s start, which shows the extent to which the Cardinal is unraveling.
Ferdinand then enters, saying that “strangling is a very quiet death.” Ferdinand continues talking to himself as Bosola hides. Now Antonio and a servant enter, and Antonio says that he hopes to find “him” at his prayers; Antonio is saying that he hopes he can find the Cardinal while he’s praying because that will be the best time to make peace with him. In the darkness, however, Bosola thinks that Antonio is the Cardinal and Bosola stabs him. Antonio cries that the long plea he had planned to reconcile with the Cardinal has been ended in a minute. When the servant returns with a lantern, Bosola realizes his mistake. Bosola, distraught, says that he would have sacrificed his own life for Antonio’s if he could have. He says that he wants to tell Antonio about the Duchess and their children before Antonio dies, and Antonio cuts him off to say that their names are kindling life in him. But Bosola continues on to say that they have been murdered.
The accidental stabbing of Antonio might be comedic if it weren’t so tragic. Due to mistaken identity, his whole plan to plead and reconcile with the Cardinal is prematurely ended. Upon realizing his mistake, Bosola reveals just how far he has turned: he was willing to sacrifice his own life for Antonio’s to make up for his role in the destruction of the Duchess’s family. Similar to the brief moment of hope provided before the Duchess dies, Bosola mentions the Duchess and her children. This mention fills Antonio with life and hope, but, tragically, Bosola immediately sinks that hope by telling Antonio that his family is dead.
This horrible news prompts Antonio to say that he’s glad he’s dying, since he no longer has any use for his life. He reflects on the pleasures of life, which he says have only prepared him for rest and death. Antonio doesn’t try to unravel the mistake and confusion that lead to his death. He simply asks for Bosola to give his regards to Delio, and to tell his oldest son to “fly the courts of princes,” which either means that he should escape the Duke and Cardinal, or leave the Italian court and courtly life in general. Antonio dies, and Bosola asks the servant to take Antonio’s body to Julia’s lodging. He curses the tragic misunderstanding.
By telling Antonio that his family is dead, you could argue that Bosola does him a favor, since it makes it easier for Antonio to accept his death. Like the Duchess does when she thinks Antonio and the children are dead, Antonio completely loses all will to live. His only hope is for his eldest son to escape with his life and to live outside of a corrupt government. We can note that Antonio doesn’t even call for revenge against the Cardinal and Ferdinand.