Dai Li
Posing as Kyoshi Warriors, Azula and her friends infiltrate Ba Sing Se and befriend Earth King , who tells them about the planned invasion of the Fire Nation during an upcoming solar eclipse. Azula also comes to understand that the secret police and intelligence agency known as the Dai Li is the key to power in the capital. She is discovered as an infiltrator by Dai Li agents and brought before their imprisoned leader, . Having in fact intentionally exposed herself, Azula lulls him into a false sense of control and accepts his offer to help stage a coup d'état against the Earth King and the loyalist Council of Five. Immediately after her seizure of power, Azula betrays Long Feng and assumes permanent leadership of the Dai Li. She also encounters Zuko in the city and convinces him to join her in order to redeem himself. During their showdown, Azula strikes Aang with a bolt of lightning while he is in the Avatar State, though he is later revived by Katara. Azula then orders the Dai Li to tear down the walls of Ba Sing Se, exposing the city to an invasion and occupation by the Fire Nation.