Someone had spent time with her - someone well-practiced in the art of pain... Three years ago former Grant Country medical examiner Sara Linton moved to Atlanta hoping to leave her tragic past behind her. Now working at a doctor in Atlanta's Grady Hospital she is starting to piece her life together. But when a severely wounded young woman is brought in to the emergency room, she finds herself drawn back into a world of violence and terror. The woman has been hit by a car but it soon becomes clear that she has also been brutally attacked. Her body is covered in old bruises and blood, her face is clawed, there are tears in her skin as if hooks had been embedded in her flesh and a rib has been forcibly removed. When Special Agent Will Trent of the Criminal Investigation Team returns to the scene of the accident he stumbles on a torture chamber deep underground, and it becomes clear that Sara's patient is just the first victim of a sick, sadistic killer .