When a park ranger is executed in the shadow of Montana's Bitterroot backcountry, federal agent Jace Holloway follows a trail of silence into a mountain range that doesn't forgive outsiders. Financial investigator Avery Sinclair is chasing a different kind of ghost — a logging company whose books don't add up, whose profits trace back to a smuggling pipeline stretching far beyond U.S. borders. The two threads collide in the territory ruled by Roman Briggs, a crime boss who built his empire on former military contractors, men who know the canyons better than the rangers who patrol them. When helicopter pilot Miles Keegan is shot out of the sky and left stranded deep in hostile terrain, Holloway and Sinclair are forced off the grid — through collapsing fire towers, black-throated caves, and a river running high with spring melt — hunted every step of the way by men who were trained never to lose.