Alfred A. Knopf Books for Young Readers, an imprint of Random House Children’s Books, has announced a YA psychological thriller from Jennifer Niven. When We Were Monsters will publish on September 2, with a simultaneous release in the U.K. and British Commonwealth under Penguin Random House UK. Katherine Harrison, executive editor at Knopf Books for Young Readers, acquired world rights for the project from Kerry Sparks at Levine Greenberg Rostan Literary Agency.

This new entry in Niven’s catalogue marks a shift in genre. Her previous works such as Holding Up the Universe and All the Bright Places, which celebrates 10 years in print this year and was adapted to a Netflix film, are titles known for making readers cry, particularly on BookTok.

The book follows a group of students at an elite boarding school, who all share grievances with a teacher. When that same teacher turns up dead, each of them are now a suspect, and they’ll all do whatever it takes to hide their secrets.

In a statement, Harrison called When We Were Monsters “a deliciously twisted dark academia thriller, and an exciting next step for Jennifer as an author. This is a story with teeth. And I couldn’t be more delighted to play a role in bringing it to the world.”

“I love exploring the complexities of characters and their emotional journeys in my writing,” Niven said in a statement. “Now, in this new book—a thriller!—I have the opportunity to delve into those complexities with a new kind of tension and explore the darker sides of human nature. While I’ve made many readers cry in the past, I’m ready to take them on a ride filled with heart-pounding suspense.”