Long ago, there were four nations - the mighty Earth Kingdom, the powerful Fire Nation, the brave Watertribes, and the peaceful Air Nomads, one country for each element. The Avatar was the only one who could master all four elements, and it was the Avatar's job to keep balance between the nations, and between our world and the spirit world. This went on for thousands and thousands of years, and every time the Avatar died, he or she would be incarnated into the next nation. Until one day, just when the world needed him most... the Avatar vanished.

[Dramatic pause is go.]