Season One (Book One: Water)
Katara, a fourteen-year-old Waterbender girl, and her brother the fifteen-year-old Sokka, find Aang and Appa in an iceberg. After Aang is revealed to be the Avatar, the three travel to the Northern Water Tribe so that Aang and Katara can learn Waterbending. En route, Aang and friends visit the Southern Air Temple, where Aang discovers the genocide of his people and encounters the spirit of his predecessor Avatar Roku, after which he finds the last winged lemur of the air temples, Momo. Throughout their journey, the trio are pursued by Prince Zuko, the exiled son of Fire Lord Ozai, who seeks to reclaim his honor by capturing the Avatar. Zuko travels with his uncle Iroh, a legendary Fire Nation general and the older brother of Ozai. Competing with Zuko for the Avatar is Commander Zhao, later to become Admiral Zhao, who leads an attack on the Northern Water Tribe. Zhao’s rather megalomaniacal attack plans, which include slaying the physical incarnation of the Moon Spirit and wreaking havoc on the entire world, are stopped by Aang and his friends, with assistance from Iroh and Zuko. As such, the Fire Lord orders his daughter Azula to capture Zuko and Iroh, who are now considered traitors to the Fire Nation.