The national parks where Ranger Jo Lockwood works, on the edge of the NSW outback, are untamed stretches of dry forest cut through with wild rivers. She's often alone, and she likes it that way until she discovers the body of a man, brutally murdered, in a vandalised campground. Detective Senior Sergeant Nick Matheson knows organised crime and gang violence from the inside out. He's so good at undercover work that his colleagues aren't sure which side he's really on. His posting to the north-western NSW district of Strathnairn is supposed to be an uneventful return to normal duties, but the murder victim in the campground is only the first of Jo's discoveries. As Jo and Nick uncover drugs and illegal weapons stashed in the wilderness, the evidence points towards locals young, rural men already on the wrong side of the law. But as far as Nick's concerned, it doesn't add up. When the bodies start mounting each brutally punished before death he becomes convinced that one person is behind the killings, one person is manipulating the lads to commit horrific crimes, forming them into his own private drug-dealing cartel. Jo has seen the man's face, and now she's his next target. Nick's determined to protect her, but trapped in rugged country in scorching summer heat, pursued by experienced shooters who can't afford to fail, they'll need all their skills and knowledge to survive.