Weeks after the fall of the Earth Kingdom, Aang and his friends must infiltrate the Fire Nation. Katara meets her father for the first time in years. Zuko returns home, but is uneasy with his newfound reputation.
After deciding he's the least valuable member of the team, Sokka seeks an apprenticeship with a sword-master. The rest of the gang tries to adjust to being without him. The imprisoned Iroh may not be as beaten as he seems.
On a forced vacation, Zuko, Azula, Ty Lee and Mai try to blend in with normal teenagers and learn about themselves and one another. Aang and company are attacked by an ominous assassin.
As the invasion approaches, Aang has recurring nightmares about being unprepared to face the Firelord. Zuko feels the perks and pressures of being the prince again.
Zuko makes a decision about his future. Aang reunites with many of his old friends in a full-scale invasion of the Fire Nation capitol to coincide with an eclipse which will remove the Fire Nation's powers.