Raine Stockton and her high-spirited, big-hearted golden retriever, Cisco, are accustomed to being heroes wherever they go. But there's a new dog in town, and Raine and Cisco find themselves unexpectedly upstaged by a flashy K-9 addition to the sheriff's department. Nike and her handler, Jolene, are part of a new government-funded program for law enforcement agencies, and though Raine admires Nike's talent almost as much as she resents Jolene's arrogance, she can't help wondering why the Department of Homeland Security would send such an expensive gift to their sleepy, little Smoky Mountain community.

Sheriff Buck Lawson has his hands full with an upcoming election, a bizarre murder, and a special appearance by a celebrity politician at the Fourth of July parade, and he is not about to look a gift horse - or dog - in the mouth. But when things go horribly wrong at a children's camp just outside of town, where Raine and Cisco are spending the holiday weekend, the scattered puzzle pieces begin to form a terrifying picture. In a desperate battle against an enemy whose face they can't even see, Raine, Jolene, Cisco, Nike, and Buck must work together and reach for depths of courage they never knew they had to save the lives of those they love.