3 books in series

Avatar: The Last Airbender: The Promise

Avatar: The Last Airbender: The Promise is a 3-book series with 3 released primary works first released in 2012 with contributions by Gene Luen Yang, Bryan Konietzko, and Michael Dante DiMartino.

Avatar: The Last Airbender - The Promise, Part 1
The Promise, Part 2
Avatar: The Last Airbender - The Promise, Part 3