The story follows 14 year-old Katara, a young girl who lives at the Northern Water Tribe, and the only Waterbender left in the whole tribe. Fire Lord Sozin was succeeded by his son, Fire Lord Azulon, and then succeeded by (and still reigning) Azulon's second son, Fire Lord Ozai. Unknown to him, the Avatar was not killed, and instead labeled him 'The Last Airbender'. In an attempt to kill the Avatar, Fire Lord Sozin used the passing of a comet later named Sozin's comet, to kill the Air Nomads. Aangs Avatar state kicked in, and saved them, by sealing them inside a ball of ice, freezing them. Flying through the sky on his companion A Flying Bison by the name of Appa they flew into a storm, where they were forced down into the water. Aang soon heard that he would be sent away to another Air Temple, away from everyone he knew, and, fearfull of his new responsibilities, and of the Seperation, Aang ran away.

Aang's mentor/guardian, Monk Gyatso, didn't approve of Aang knowing at such a young age, but was hushed. Aang was then told that he was the Avatar, at a young age, as they elders believed that war was approaching. Many years later, Avatar Roku died, with the help of Fire Lord Sozin, and was then reborn into the next Avatar, Aang, a young Airbender from the Southern Temple. But, his close friend, Avatar Roku, warned him against the act, and threatened to take action against his friend disrupted the balance. More than 100 years before the opening of the story, th ruler of the Fire Nation, Fire Lord Sozin, planned a world war to expand the Fire Nation.

Avatar the last airbender book 3 the puppet master