At the end of Act 5, Scene 2, Bosola tells the Cardinal that he is ready to kill Antonio, but once the Cardinal leaves, Bosola reveals that he is committed to saving Antonio from both the Cardinal and his murderous brother Ferdinand. Bosola’s time alone onstage allows him a moment to reflect on the situation, as he delivers a soliloquy about the things he’s witnessed and what he has resolved to do about it. This soliloquy allows Bosola to spill his innermost thoughts, revealing them to the audience. After lying to the Cardinal, he is able to reveal his true plan without giving himself away to any of the other characters. He makes a vow to Antonio:
I’ll seek thee out, and all my care shall be
To put thee into safety from the reach
Of these most cruel biters that have got
Some of thy blood already.
Bosola uses soliloquy in this scene to reveal his true intentions and to steel himself for the task at hand. But this individual soliloquy is part of a larger pattern throughout the play. Bosola is the character with the most lines, and it is his tortured conscience that is highlighted by his time alone onstage. His ability to reflect on how he has been complicit in the murder and violence throughout contextualizes the changes in his behavior and ideology. This moment is an important turning point in Bosola’s journey, and it is strengthened by the placement of this soliloquy, which gives Bosola a moment alone to decide that he needs to make things right.