Zack Tolliver left the Federal Bureau of Investigation to spend more time with his family. He is at home when Libby's sister calls, worried about her daughter Pru in the wake of the horrific murder of a high school classmate. Libby goes to Kanab, Utah, to offer support. She discovers Pru's life is indeed in danger. Zack investigates and learns the murder may be tied to old bones in a hidden cave on the summit of Canaan Mountain. He goes to Kanab to join Libby and begins an investigation that leads from a single murder to a much larger conspiracy.