After a grueling mission, Sarah Barney and her BAU team take a much-needed vacation to heal and recover. But their peace is shattered when a series of brutal murders begins terrorizing both the UK and France. The victims are slaughtered in a horrific pattern, throats slit, eviscerated, and hung from iconic landmarks by their own intestines.
Interpol calls in Sarah's team to help track down the killer, whose methods are as calculated as they are sadistic. As the investigation intensifies, Sarah discovers that the case is far more personal than she ever imagined. The killer isn't just any criminal, he is linked to someone from Sarah's past, and whose dark secrets now threaten everything she holds dear.
As Sarah hunts down a monster, she's forced to confront her own demons and the chilling truth about her connection to the killer. In a world of shadows, how much can Sarah trust her instincts, and who can she turn to when the enemy is closer than she ever feared?