When M. Night Shyamalan’s fantasy film The Last Airbender — panned by both critics and fans of the wildly popular TV series on which it was based — flopped majestically at the box office, it looked like the end of a valuable franchise.

But now, with The Legend of Korra, which premieres Saturday on Nickelodeon, Bryan Konietzko and Michael DiMartino, the creators of Avatar: The Last Airbender have been given a rare chance to rebuild a world that was taken away from them.