This is during Act 5, Scene 5 of the play. At the beginning of the scene, the Cardinal is pondering the nature of hell when Bosola enters, along with a servant carrying Antonio's body. Bosola tells the Cardinal, "I am come to kill thee." The Cardinal cries, "We are betrayed!" and Pescara, Malatesti, Roderigo and Grisolan then enter.
The Cardinal tries to tell them that he is being attacked, but they don't believe him, thinking it to be a ruse. To ensure nobody will enter to help him, Bosola kills the servant and then stabs the Cardinal. However, Ferdinand breaks in and gives Bosola his death wound. In retribution, the dying Bosola kills Ferdinand. When Pescara, Malatesti, Roderigo and Grisolan come in and find the carnage, Bosola explains that it was done in revenge for the Duchess of Malfi. The Cardinal finally dies; Bosola gives a soliloquy on the nature of life and then also dies. When Delio and Antonio's son arrive, they are "come too late" to offer any assistance.