Avatar: The Last Airbender (Book Three: Fire)

Aang wakes up from his battle with Azula to discover that Ba Sing Se has fallen and the world thinks he's dead. So he and his friends set off undercover across the Fire Nation to find Fire Lord Ozai before the Day of Black Sun. Prince Zuko returns home as the triumphant son, but soon finds the honor he so greatly craved from his father is worthless. New alliances are formed and Team Avatar forges a new plan to stop the Fire Lord. But will they find him in time?