After a state trooper is killed under mysterious circumstances, Oregon State Police sergeant Maggie Blackthorne is assigned to the case. The investigation takes her to Desolation Ridge in the Umatilla National Forest, where the suspect is reported to be hiding out with a possible hostage. It’s late fall. Daylight is scarce, and there is a fierce chill in the air. To make matters worse, a deadly cougar has been spotted nearby. But as Maggie and her partner Hollis trudge on, uncovering clues and dealing with their own tense past, one thing is clear: Somewhere amongst these towering pines, a murderer is watching them.