New York Times bestselling author Catherine Ryan Hyde returns with an unforgettable story of courage. 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. With the help of three locals--a fearless seventy-year-old widow, a pack guide, and a former actor with limited outdoor skills--he heads into the wild. The days that follow transform Ethan's world. Hail, punishing sun, swollen rapids, and exhausting pain leave him wondering if he's been fooled yet again: Is his father out here at all? As the situation grows increasingly dire, Ethan realizes this quest has become about more than finding his dad. From the bestselling author of Pay It Forward comes a story of nature revealing human nature--the trickiest terrain. Navigating an unforgiving landscape, Ethan searches himself for the ability to forgive his father--if he finds him alive.