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.

With a teenage girl also missing and the Jane Doe seriously ill,the clock is ticking for Darby as she hunts for the dungeon before anyone else disappears or dies. And when the FBI takes over the investigation, it becomes clear that a sadistic serial killer has been on the prowl for decades - and is poised to. strike again at any moment. A killer with links to horrors that Darby has tried desperately to bury in her past...