Allison Parker is on the run with her teenage daughter, Hannah, and Colter Shaw has been hired by her eccentric boss, entrepreneur Marty Harmon, to find and protect her. Though he's an expert at tracking missing persons--even those who don't wish to be found--Shaw has met his match in Allison, who brings all her skills as a brilliant engineer designing revolutionary technology to the game of evading detection. The reason for Allison's panicked flight...

Seventeen-year-old Ethan Underwood is totally unprepared to search for his father in the Blythe River National Wilderness. Not only is he small, scrawny, and skittish but he's barely speaking to the man after a traumatic betrayal. Yet when his father vanishes from their remote cabin and rangers abandon the rescue mission, suddenly it's up to Ethan to keep looking. Angry or not, he's his father's only hope.