Long ago, the Avatar, the master of all four elements, maintained the harmonious balance between the four nations. But when the world needed him most, he vanished without a trace. A hundred years later, young waterbender Katara and her brother Sokka discover a boy trapped in ice. Aang is not only the last airbender but also the new Avatar. Together, the friends embark on an adventurous journey to help Aang learn his powers as the Avatar. What they don't know is that the Fire Nation is already hot on their trail...