In the Appalachian mountains, beyond the grip of civilization, lies a cove. In the cove there is a cave, and in the cave there is a tree. To those who know it, the tree holds a power thought lost with the Garden of Eden: the power of life itself.

1943: Twenty-six-year-old Merritt Garner pines for her place in the world. But as the illegitimate daughter of a Tennessee congressman, she’s an unspeakable offshoot of the family tree. Working for the TVA’s Women Officers of Public Safety (WOOPs), she takes an assignment to an isolated community of mutes, obstinate holdouts in the watershed of the TVA’s newest dam. Her job: protect Sebastian, a failed gospel singer and the agency’s best negotiator, as he does his grim duty of uprooting another community.

1996: Fifty-two-year-old Abel McCoig’s mother is dead. Returning to her rural North Carolina home the day before Christmas, he resolves to bury her before the winter sun sets. But this small community on the banks of the TVA's deepest late has not forgotten Abel. Thirty years ago, an inexplicable incident severed his tongue, wiped his memory, and disappeared the local preacher's daughter. Now, as he labors to dig a grave in the frozen churchyard, a specter from the murky past returns to deliver the fate devised for Abel before he was born.

For Abel and Merritt, only one thing seems certain: evil is rooted deep in the valley of shadow.