Fifteen years after launching the Divergent book series, Veronica Roth is returning to the franchise with two new novels.

On Saturday, the author announced at BookCon in New York City that she’s written a new companion duology, set in an “alternate universe” in which the books’ young heroine Tris didn’t choose Dauntless.

“Not a prequel, not a sequel, not a spinoff, not a different POV but an alternate universe of Divergent where Tris chooses a different faction,” explained Roth to USA Today. “I think the question of ‘who is Tris without Dauntless’ is an interesting one.”

Although The Sixth Faction, available Oct. 6, can be read as a standalone book, Roth is particularly looking forward to franchise fans’ reaction to this new perspective on the character.

Whereas the original book trilogy saw Tris choose Dauntless, the faction of bravery, in The Sixth Faction, tragedy strikes at her Choosing Ceremony, where her decision thrusts her into an underground rebellion. There, she meets a mysterious boy named Tobias ‘Four’ Eaton, Tris’ love interest in the original books.

“For existing fans, I’m excited for them to see how the old and the new fold together,” Roth teased. “You’d think that certain things wouldn’t happen because she makes a different faction choice, but she does find her way to the same people. Seeing how that happens is a really fun part of it.”

In the original books, Divergent (2011), Insurgent (2012) and Allegiant (2013), Tris Prior is a teen girl living in post-apocalyptic Chicago, where society is split into five factions. Finding out that she’s Divergent, which means she doesn’t belong to just one faction, Tris must conceal her status as a war brews.

Shailene Woodley starred as Tris in the Lionsgate film adaptations, Divergent (2014), The Divergent Series: Insurgent (2015) and The Divergent Series: Allegiant (2016), with a planned final installment, Ascendant, which was never made.

Roth expanded on the books with the 2014 short story collection Four, as well as the 2018 short We Can Be Mended, both of which were told from Four’s perspective.