When a tortured young woman enters the trauma center of an Atlanta hospital, Dr. Sara Linton is thrust into a desperate police investigation with Special Agent Will Trent and his partner, Faith Mitchell.

Though guarding their own wounds and their own secrets, Sara, Will, and Faith find that they are all that stand between a madman and his next victim. In the backwoods of suburban Atlanta, local police have set up their investigation. But Georgia Bureau of Investigation detective Will Trent doesn't wait for the go-ahead from his boss—he plunges through police lines, single-handedly exposing a hidden house of horror buried beneath the earth.

Another woman—a smart, upscale, independent young mother—has been snatched. For the two cops out on the hunt, for the doctor trying to bring her patient back to life, the truth hits like a hammer: The killer’s torture chamber has been found, but the killer is still at work.