Ex-FBI profiler Darby McCormick is contacted by a former colleague. Jackson Cooper is not the type to ask anyone for help, but he's on the trail of a woman who's been missing for twenty years. She was one of the first victims of a serial killer who has been carving a dark path across America for decades. And he may have tracked the monster to Montana. But when Darby arrives, Jackson Coop has vanished. Something is very wrong - and with no witnesses, no clues and no one to help, Darby is all alone and running out of time.