Three and a half years ago former Grant Country medical examiner Sara Linton moved to Atlanta hoping to leave her tragic past behind her. Now working as 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 naked and brutalised it's clear that she has been the prey of a twisted mind.

When Special Agent Will Trent of the Criminal Investigation Team returns to the scene of the accident he stumbles on a torture chamber buried deep beneath the earth. And this hidden house of horror reveals a ghastly truth - Sara's patient is just the first victim of a sick, sadistic killer. Wrestling the case away the local police chief, Will and his partner Faith Mitchell find themselves at the centre of a grisly murder hunt. And Sara, Will and Faith - each with their own wounds and their own secrets - are the only thing that stands between a madman and his next crime...