NEW YORK — Veronica Roth fans can start the countdown.

“The Divergent” author is set to write a new two-book series, HarperCollins Children’s Books said Monday. The books currently are untitled, with the first one expected in 2017 and the next in 2018.

Roth and her publisher offered few specifics, beyond saying the series is in “the vein of ‘Star Wars’” and will tell of a boy’s “unlikely alliance” with an enemy.

“Both desperate to escape their oppressive lives, they help each other attain what they most desire: for one, redemption, and the other, revenge,” the publisher announced.

In a recent email, Roth wrote that “The idea started with a character. All the other elements — setting, world, even a substantial portion of the plot — came after.” She added that while she had a “pretty detailed” outline for the new series she was still in the early stages of writing.

“That’s why I’m being so vague,” she explained.

“The Divergent” young adult trilogy, a Dystopian adventure Roth completed in 2013, has sold more than 30 million copies. The first “Divergent” movie, starring Shailene Woodley as teen heroine Tris Prior, came out a year ago and quickly earned more than $100 million at the box office. Three more movies are planned.

A Chicago resident, the 26-year-old Roth was still in college when she began “Divergent,” writing it in her jammies while on winter break from Northwestern University. She is now one of the world’s most popular authors.

“I think I’d have to be a robot not to occasionally worry about expectations!” she wrote to the AP. “But mostly I try to trust my instincts. It helps that I’m really in love with this project — that makes it a joy to work on.

“I’ve been really taking my time with it,” she said of the new series. “I’ve written huge sections a certain way only to cut them and start again. I’ve stepped away for a while, to work on other things, and then come back when I have better perspective. I’ve been more patient with myself and with the story. I’ve expanded my collection of comfortable pants and snack foods. It’s all working quite well so far.”