U.S. Fish and Wildlife Service Special Agent Nick Tanner goes undercover to follow up on another agent's investigation-one that may have led to her murder. From the stark canyons and soaring rock walls of Book Cliffs to the gritty back streets of Las Vegas; from the swift-flowing Green River rapids to a pastoral Utah town hiding violent secrets, Tanner is drawn into a seething vortex of a wildlife trafficking family, a crooked sheriff, a white nationalist church, and a killer with the perfect alibi. And one of them has Tanner in their crosshairs.