Season synopsis
Contains spoilers for this season and earlier seasons.
After leaving the Northern Water Tribe, Aang and his friends travel through the Earth Kingdom seeking an earthbending teacher. King Bumi says Aang needs someone who waits and listens; the search leads them to Toph Beifong, a blind fighter who has secretly mastered earthbending despite her wealthy parents’ restrictions. Toph joins and teaches Aang to stand his ground. Meanwhile, Zuko and Iroh are branded fugitives and try to build a life in the Earth Kingdom, while Zuko’s sister Azula pursues them with Mai and Ty Lee.
The group seeks a way to weaken the Fire Nation, and Sokka discovers that the coming solar eclipse will temporarily stop firebending, creating a chance for invasion. While Toph holds up Wan Shi Tong’s collapsing library, sandbenders steal Appa; the others flee into the desert without him. They bring the eclipse plan to Ba Sing Se, where officials deny the war. A search for Appa exposes Long Feng’s Dai Li secret police, and the group reunites with Appa after Zuko frees him. They then show Earth King Kuei the destroyed Fire Nation drill and prepare an invasion with Sokka’s father and the Earth Kingdom army.
As the invasion approaches, Aang begins training with Guru Pathik to unlock the Avatar State, but leaves before completing the final step when he senses Katara is in danger. Azula has infiltrated Ba Sing Se disguised as a Kyoshi Warrior and takes control with Long Feng’s help. In the crystal catacombs, Zuko sides with Azula against Aang and Katara before Azula strikes Aang with lightning. Katara escapes with the injured Aang and revives him using water from the Northern Spirit Oasis. The Earth Kingdom capital falls, the planned invasion loses its base, and Zuko begins to question the choice he made during the battle.