|Zukko follows Aang's group to the western air temple.. while trying to think of a way to come out to them as a good guy...|
Sakka, Ktarra, and Taf all agree that the only option now is for Aang to master all 4 elements and defeat the fire lord before the comet arrives. Aang still doesn't want to learn firebending because he hurt Ktarra last time he tried it, and they can't find a teacher anyway.
Zukko then shows up and says he can teach firebending. He tries to explain that he's good now, but isn't doing a great job of it, and accidentally lets it slip that he's the one who hired the bomber assassin. Ktarra and Sakka refuse to listen to him because of all the bad things he's done in the past... later, Taf tries to reason with them, and says that she could sense Zukko's sincerity. Aang wants to side with Ktarra, but he actually does know there is good in Zukko because he was aware of the few times he was saved by him.
The bomber assassin comes back, and everyone sees Zukko try to stop him and get himself hurt. Sakka fends off the assassin with a boomerang... Zukko again tries to join Aang's group. He says that he's realized that he doesn't need his father to restore his honour, and that his destiny is to help the avatar to restore balance to the world.. he apologizes for everything, including when he accidently burned Taf's feet, reacting on instinct. He explains that firebenders have to be very careful not to unintentionally hurt anybody with their powers. Upon hearing this, Aang realizes that Zukko is meant to be his firebending teacher.
Ktarra is still pissed at Zukko, and threatens to "end" his destiny if he makes another step backward towards the fire lord's side.