Finally Aaron appears, looking horrid as he smiles with half of his face missing. Todd tells him to put his gun down.
He says that he knows what Aaron wants, and it isn't him or Viola: It's Aaron.
Todd reveals to us what Ben revealed to him: The real way to become a man in Prentisstown is to kill another man, so the Mayor would select sacrifices for boys once they came of age. This way, everyone would have blood on their hands.
Aaron tries to tell Todd that he's a part of God's perfect army, but Todd denies that God has anything to do with this horrible plan.
Aaron sets his gun down and starts to pray. He tells Todd to murder him, that the only way he can be strong is through hatred. He makes it all sound like it's some predestined glory.
Aaron seems to think he's going to be some kind of martyr after all of this. Todd doesn't want to give in and kill him in cold blood, but then Aaron opens up his Noise to him, telling him how he wanted to kill Ben and hurt Viola.
And so begins another infamous Todd versus Aaron fight, complete with Viola fighting from a distance, throwing a rock at Aaron. Aaron taunts Todd, telling him that he'll never be a man, and then he bites a chunk out of his neck.
Aaron pushes Viola over, causing her to fall and start bleeding on the rocks, so Todd gets Aaron on the ground and starts punching him. Like, to a pulp. But the guy still won't die. Todd is blinded by his red Noise of anger, and is apologizing without even knowing why.
In a valiant move, Viola takes the knife and plunges it into Aaron's neck. He struggles on the edge of the rocks and his Noise finally stops as he falls over the edge—dude is finally dead. The knife goes with him.