Synopsis: Aang and Appa are awoken a hundred years later by two siblings of Southern Water Tribe origin, Katara and Sokka. Aang learns that the Fire Nation started a war a hundred years ago, just after his disappearance. The Fire Nation's opening move in its campaign for global conquest was to launch a genocidal attack on the Air Nomads which drove Aang's entire race to extinction, thus making him 'the last airbender' left alive. He realizes that he must fulfill his destiny of becoming a fully realized Avatar and return balance to the world by defeating the Fire Nation. Aang sets out to master the three unlearned elements: water, earth, and fire. With Katara and Sokka, Aang decides to head first to the North Pole to find a waterbending master.