A massive fight breaks out. Aang chases after Bumi's coffin while being pursued by Azula. This marks their first real confrontation, where Aang realizes how dangerous and precise her blue flames are. Meanwhile, Mai and Ty Lee (Azula’s childhood friends) face off against Katara and Sokka.
In the episode Aang, Katara, and Sokka return to the Earth Kingdom city of Omashu, hoping to find King Bumi so he can teach Aang earthbending. However, they are shocked to find the city has been conquered by the Fire Nation and renamed "New Ozai." The Infiltration [S2E3] Return to Omashu
Aang goes to the secret location to meet Bumi, who is being held in a metal coffin suspended high in the air. Just as the trade is about to happen, —Zuko’s sister—intervenes. She has arrived to take over the operation and finds the trade "unacceptable." A massive fight breaks out
During a chaotic attempt to help the citizens escape, the governor of the city's toddler son, , accidentally ends up with the resistance. The Fire Nation governor assumes the Avatar has kidnapped his son and offers a trade: the boy for King Bumi . Meanwhile, Mai and Ty Lee (Azula’s childhood friends)
The trio sneaks into the city using a "purple pentapus" trick—letting the tiny creatures bite them to create fake red marks that look like "pentapox," a highly contagious (and made-up) disease. The guards, terrified of catching it, let them pass. Inside, they meet a resistance movement led by local citizens who are trying to evacuate the city.