Long ago the four nations lived together in harmony. Then, everything changed when the Fire Nation attacked. Only the Avatar -master of all four elements- could stop them. But when the world needed him most, he vanished.

A hundred years passed and my brother and I discovered the new Avatar, an airbender named Aang; and although his airbending skills are great, he has a lot to learn before he’s ready to save anyone. But I believe Aang can save the world. 

(Source: how-ood)