Four years ago, Theresa Herrera's ten-year-old son was abducted. The police found little evidence and the case went cold. Then a woman comes forward and promises to reunite Theresa with Rico - but only if Theresa is prepared to pay a very high price indeed.

When Boston CSI Darby McCormick finds a raving and emaciated woman hiding at the scene of a violent kidnap, she runs a DNA search to identify the Jane Doe. The result confirms she was abducted five years earlier and has somehow managed to escape from the dungeon in which she's been caged.

When Judith Chen is found floating in Boston's Harbour, links are made with the murder of Emma Hale, a student who vanished without trace, only for her body to wash up months later.

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 all the while the killer is watching, circling his next target: her. She must not only meet evil and survive, but also be prepared to face this small town's dark heart.