In the trauma center of Atlanta's busiest hospital, Sara Linton treats the city's poor, wounded, and unlucky--and finds refuge from the tragedy that rocked her life in rural Grant County. But then a tortured young woman becomes a patient in her ER. . . .

In the backwoods of suburban Atlanta, where Sara's patient was found, 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 . . . and then finds another victim.

Wresting the case away from the local police chief, Will and his partner, Faith Mitchell, are called into a related investigation. 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.

With Undone, Karin Slaughter weaves together the moving, powerful human stories of three unforgettable characters from her New York Times bestselling novels Faithless and Fractured, who collide for the first time in an electrifying race against the clock--and a duel with unspeakable human evil.