Back in her hometown of Black Falls, Vermont, Secret Service agent Jo Harper is drawn into the search. But her efforts face an unexpected challenge: Elijah Cameron. With his military training and mountain rescue experience, Elijah knows the unforgiving terrain better than anyone. But he and Jo have been at odds forever - and Elijah believes the missing teenager isn't just lost... she's on the run. Forced to work together, Jo and Elijah battle time and the elements in a race into the unforgiving mountains. The twists and turns awaiting them will take them closer to the explosive truth... and into the sights of a killer.