Avatar Book 2 Earth Episode 19-20 - The Guru / The Crossroads of Destiny >Zuko prepares to capture the Avatar, but before he can do so, Azula takes control of the Dai Li and has Zuko imprisoned alongside Katara. Zuko and Katara discover they share a lot in common. When Aang, aided by Iroh, attempts to free Katara, Zuko is told by his uncle that he must carefully consider the path that his next actions will set him upon. To Iroh's dismay, Zuko chooses to help Azula attack the Avatar. In the battle that follows, Aang realizes that he must let go of Katara in order fulfill his destiny, and meditates into the Avatar state, but Azula hits him with lightning while in the Avatar State, putting the Avatar near the brink of death. Iroh delays Azula, Zuko, and the Dai Li long enough to allow Katara to escape along with the gravely injured Aang, and then is taken prisoner as a traitor to the Fire Nation. Katara uses a vial of spirit water given to her at the North Pool in order to save Aang. With the deposed Earth King Kuei in tow, the team flees Ba Sing Se, now in the hands of the Fire Nation after a century of resistance.