After a harrowing encounter with juvenile sociopath Simon Gutmunsson, junior FBI consultants Emma Lewis and Travis Bell went their separate ways: Emma rejected her Quantico offer, and Travis stayed to train within a new unit of the Behavioral Science division. But the unit's latest case is feeling eerily familiar, and Kristin Gutmunsson-Simon's eccentric twin-reaches out to Travis to send a warning: Emma is in peril.

When new evidence points to a copycat of Daniel Huxton, the serial killer that she escaped, Emma returns to Quantico and is thrown back into her past traumas. Compelled to prevent more tragedy-even if it means putting herself in danger-she looks to Simon once again. But can he be trusted to help stop the killer before time runs out for his next victims?