A summer at his grandparents' South Dakota ranch is not eleven-year-old Cooper Sullivan's idea of a good time. But things are a bit more bearable now that he's discovered the neighbor girl, Lil Chance, and her homemade batting cage. Each year, with Coop's annual summer visit, their friendship deepens from innocent games to stolen kisses, but there is one shared experience that will forever haunt them: the terrifying discovery of a hiker's body. As the seasons change and the years roll by, Lil remains steadfast to her aspiration of becoming a wildlife biologist and protecting her family land, while Coop struggles with his father's demand that he attend law school and join the family firm. Twelve years after they last walked together hand in hand, fate has brought them back to the Black Hills when the people and things they hold dear need them most. When small pranks and acts of destruction escalate into the heartless killing of Lil's beloved cougar, memories of an unsolved murder in these very hills have Coop springing to action to keep Lil safe. Lil and Coop know the natural dangers that lurk in the wild landscape of the Black Hills. Now they must work together to unearth a killer of twisted and unnatural instincts who has singled them out as prey.