FBI Agent Riley Paige faces a calculating serial killer who turns abandoned classrooms into macabre crime scenes, complete with unsolved math problems on the blackboard. As each equation leads closer to long-hidden victims, Riley must confront a past haunted by loss and a future threatened by a murderer’s cold logic.

FBI Agent Riley Paige faces a calculating serial killer who turns abandoned classrooms into macabre crime scenes, complete with unsolved math problems on the blackboard. As each equation leads closer to long-hidden victims, Riley must confront a past haunted by loss and a future threatened by a murderer’s cold logic.