Aang and the gang discover an Earth town that celebrates something called "Avatar Day." But when they get there and learn the festival is of "anti-Avatar" sentiment and Aang is put on trial for a crime a past incarnation allegedly committed. Looking to clear the Avatar's good name, Katara and Sokka venture back to a familiar place to gather evidence and discover the truth.

Aang searches for Appa while Katara struggles to keep everyone together to survive in the vast desert. Meanwhile, Iroh and Zuko seek help from an ancient secret society.

The kids battle Long Feng and the Dai Li when they attempt to show the Earth King the vast conspiracy taking place in his city. Zuko becomes seriously ill and has feverish dreams as he faces a spiritual crisis.

Zuko, Azula, Mai and Ty Lee take a vacation to Ember Island. In the process, they come to learn more about themselves and each other as well as their desires for the future. Elsewhere, Aang and the others face off against a new adversary.

Sokka wants to break his father out of jail and asks Zuko for information on Fire Nation prisons. Sokka and Zuko head for the Boiling Rock, a prison located in the middle of a volcano, to rescue Sokka's father.

Zuko and Sokka make new plans to break out of the prison with Suki, Sokka's father and some others while a shocking twist leaves Azula none too happy with her two closest friends.