The gang hides out in the Western Air Temple. Zuko tries to convince the gang of his change in heart, but they are very hesitant. Combustion Man/Sparky-Sparky Boom Man attacks again.
Zuko has joined up with Aang's group and is now ready to teach Aang fire bending. Unfortunately, Zuko has found out that he has lost his ability and must now relearn it. Zuko and Aang travel to find the original source of fire bending.
Sokka and Zuko head to the Fire Nation's most heavily guarded prison, the Boiling Rock, in hopes of finding and breaking out the captured invasion force.
The escape is planned and the heroes attempt to break from the prison that very day. But problems come when Azula, Mai and Ty Lee arrive at the prison.
Sozin's Comet is only three days away. Zuko tells the others what the Fire Lord plans on the day of the comet and the gang realizes that they must stop him before then. But Aang doubts that he can do what is expected of him.
Aang awakes on a mysterious island and confronts his past lives for advice on how to stop the Fire Lord without killing him. The rest of the group searches for Aang.
Aang's moment of truth arrives. Can he defeat Ozai, the Phoenix King? Will he be forced to take a human life? All the characters face their greatest challenges.