Mary Crow is running for DA, trying to unseat the incumbent George Turpin. In mid-campaign a stray dog digs up shocking new evidence that breathes life into a decades-old murder of a nine-year-old girl. Pisgah County thinks the most likely suspect is Zack Collier, an autistic man who's also the son of one of Mary Crow's campaign volunteers. When the police start harassing Zack yet again, his mother begs Mary for help. Against the advice of her campaign manager, she agrees to represent the compromised man.
Mary stops the police abuse, but she realizes that the true killer must be found if Zack and his mother are to ever be free of rumor and innuendo. She enlists the aid of retired detective Jack Wilkins, who's been obsessed with this murder since the day it happened. Eager to solve this final mystery of his life, he agrees to work for Mary.
Mary and Jack join forces, along with SBI agent Victor Galloway. In the midst of her political campaign, Mary must save Zack and his mother when attacks against them grow from rumor into physical danger. Only when Mary discovers the true killer does her campaign rhetoric hit home-that all people are innocent until proven guilty.
