When does Avatar: The Last Airbender return?

Avatar: The Last Airbender is an American animated fantasy action television series. It originally aired on Nickelodeon for three seasons from February 2005 to July 2008. It is set in a largely Asian-inspired world in which some people can telekinetically manipulate one of the four elements. The only individual who can bend all four elements, the "Avatar", is responsible for maintaining harmony among the world's four nations. The extended franchise includes an ongoing comics series, a prequel novel series, an animated sequel series, and a live-action film.