After leaving the Northern Water Tribe, Aang continues to master Waterbending under Katara’s tutelage as the group searches for an Earthbending teacher. Their search brings them to Toph Beifong, a twelve-year-old blind tomboy and Earthbending prodigy who wants independence from her upper-class family. Pursued by Azula, Zuko and Iroh lead new lives in the Earth Kingdom, first as wanderers and later as refugees in the capital of Ba Sing Se. At a library guarded by the spirit Wan Shi Tong, Aang and his group learn that an imminent solar eclipse could allow them to stop the Fire Nation before Sozin’s Comet arrives. Their journey to Ba Sing Se to inform the Earth King of this is complicated when Appa is kidnapped. At the city, they find the Earth King Kuei and Ba Sing Se manipulated by Long Feng, the leader of the Dai Li secret police.
After Aang’s group finds Appa and exposes Long Feng, Toph is captured, but escapes by ”Metalbending”, while Aang attempts to consciously access the Avatar state. The Dai Li join Azula to instigate a coup d’état of Ba Sing Se; and Zuko, having tried to ignore his past obsession, relapses when the Avatar appears to rescue Katara. As Aang tries to enter the Avatar state, Azula nearly kills him. With Ba Sing Se and the Earth Kingdom now under Fire Nation rule, the group escapes thanks to Iroh, who is imprisoned for betraying the Fire Nation, and Kuei goes into hiding.