Fear grips a town in Colorado as a murderer targets entire families in their own homes. As police and the FBI struggle to contain the situation, they bring in forensic investigator and serial killer expert Darby McCormick. What she finds is a brutal and elusive predator who stays one step ahead of their investigation. As Darby navigates the blood-ties and broken promises that divide the locals, she knows that all the while the killer is watching, waiting and circling his next target: her. She must not only meet evil – and somehow survive – but also be prepared to face this small town's dark heart …