The world of Avatar: The Last Airbender is set to expand once more in a series of original novels.

EW can exclusively announce that Nickelodeon has partnered with Abrams Children’s Books for a new series of YA novels set in the universe of The Last Airbender, and centered on Avatar Kyoshi, the longest-living human Avatar in history at over 230 years old, whom fans know very little about. The two books included in the deal will be written in consultation with Michael Dante DiMartino, the co-creator and executive producer of The Last Airbender and its follow-up The Legend of Korra. F.C. Yee (The Epic Crush of Genie Lo) serves as author.

The first of the two books, The Rise of Kyoshi, will be explore her origin story as she established the brave and respected Kyoshi Warriors, but also founded the secretive Dai Li, which led to the corruption, decline, and fall of the Earth Kingdom. “Avatar Kyoshi is one of the characters fans often ask me about, so I’m excited to have the opportunity to help expand on her legend,” DiMartino said in a statement.

Avatar: The Last Airbender ran for three seasons on Nickelodeon, from 2005 to 2008, eliciting acclaim for its animated design, characterization, and world-building; it went on to win Emmy and Peabody Awards, and has built a significant fandom in the decade since it went off the air. A sequel, The Legend of Korra, ran from 2012 to 2014, and several comics and graphic novels based on the original series have been published, including the series The Lost Adventures (2005-2011), which took place between events of the show.

“We’re thrilled to be partnering with Michael Dante DiMartino, Nickelodeon, and critically acclaimed author F.C. Yee to add to the canon of Avatar: The Last Airbender,” said Andrew Smith, senior vice president and publisher of Abrams Children’s Books. “Bringing Kyoshi’s previously untold story to life in original novels will be a major pop culture event, not only for fans of the show, but also for readers hungry for a new epic YA saga. The Rise of Kyoshi has all the hallmarks of what YA readers love — bold storytelling set in a rich landscape with a strong heroine at the forefront!”