Book 2 Chapter 1 "THE AVATAR STATE"

Aang and his friends travel to an Earth Kingdom base from which they are to be escorted to Omashu, where Aang intends for King Bumi to teach him earthbending. At the base, General Fong suggests that Aang can defeat the Fire Lord and end the war immediately by using the Avatar State. After many failed attempts, General Fong finally succeeds in triggering the Avatar State by faking Katara's death, which leads to Aang nearly destroying the base in rage. The spirit of Avatar Roku warns Aang that the Avatar State is a defense mechanism that empowers Aang with the skills and knowledge of all his past lives, though there is a catch: if he is killed in the Avatar State, the reincarnation cycle will be broken, causing the Avatar to cease to exist. The group decides to travel to Omashu alone. Meanwhile, Zuko and Iroh are visited by Zuko's younger sister, Azula, who has come bearing a message from the Fire Lord, requesting their return home. A guard accidentally reveals that the summons is a ruse in order to imprison them as traitors. They manage to escape, but are forced to become fugitives and cut off their topknots.