"Before being promoted to detective, Carrie Santero was given a rare glimpse into the mind of a killer. Through her mentor, Jacob Rein--a seasoned manhunter whose gift for plumbing the depths of madness nearly drove him over the brink--she was able to help capture one of the most depraved serial killers in the country. Now, the discovery of a small human foot buried in the Pennsylvania woods will lead her to a decades-old cold case--and the darkest...