Ben may not have burned any bridges, but there are still plenty of ashes that need to cool before they can go home. With Hagesboro behind them, they wander southward in search of what Nathan needs to pull his head together. The name of the angel that dwells inside him. The name that will invoke its true nature, and restore its control.
What will happen, when the soulless creature inhabiting Nathan is fully in possession of his living mind? Neither of them know. They're both afraid of it, but it's something that has to happen.
Nathan's losing control of the power that rightfully belongs to the creature other angels call The Death. He's losing his perspective, and his ability to restrain himself is going along with it.
The long journey south gets even longer as they struggle with that reality. In one final, desperate push, Nathan seeks the answer he needs. There's a question he's run from all his life, because he fears what it means to know the answer.