"That's why it's called justice: 'Cause it's just us!"
Aang, Katara, and Sokka come across an isolated Earth Kingdom village which celebrates something called "Avatar Day". However, upon visiting the village, the team finds that the villagers are of an anti-Avatar sentiment, claiming that Avatar Kyoshi had killed their leader, Chin the Great. Shocked and dismayed by this, Aang resolves to stand trial in Kyoshi's stead, and Sokka and Katara are left to find evidence of the previous Avatar's innocence.
Meanwhile, Zuko has donned his Blue Spirit identity, and is stealing from Earth Kingdom villagers. When Iroh confronts Zuko about this, Zuko decides to split from his uncle and find his own way in the world.
Aang manages to resolve the court issue by channeling the spirit of Avatar Kyoshi. To everyone's surprise, she pleads guilty to the charge of slaying Chin the Great... a megalomaniac conqueror bent on subjugating her people. When it became clear that diplomacy would not solve anything, Avatar Kyoshi separated her people's peninsula from the mainland, creating the "Kyoshi Island" territory seen in the first season, and sending Chin the Great plummeting to his doom
. Deliberations are interrupted by a band of Fire Nation raiders, the "Rough Rhinos," who arrive and start busting up the town; Aang is sentenced to the "community service" of seeing them off. The final scene is of Aang, Katara and Sokka in the center of a no-longer-sarcastic Avatar Day.