The world is divided into four kingdoms, each represented by the element they harness, and peace has lasted throughout the realms of Water, Air, Earth, and Fire under the supervision of the Avatar, a link to the spirit world and the only being capable of mastering the use of all four elements. When young Avatar Aang disappears, the Fire Nation launches an attack to eradicate all members of the Air Nomads to prevent interference in their future plans for world domination.