Bree Nichols and her search and rescue dog Samson discover a crying infant in the densely forested woods outside of Rock Harbor, Michigan. Against objections from her husband, Kade, who knows she'll become attached, Bree takes the baby in. Quickly she begins a search for the mother-presumably the woman reported missing just days earlier.

While teams scour the forests, Bree ferrets out clues about the missing woman. But she soon discovers something more shocking: Bree's former husband-long presumed dead in a plane crash-resurfaces. Is he really who he says he is? And should she trust him again after all these years?