In the hills and isolated mountain enclaves of southern Appalachia, Nana Grace has left her own family behind to become the "Shepherd" of a disaffected flock of worshippers that she keeps in thrall through her charismatic preaching and the dispensing of stolen drugs. Her daughter, Jane, struggles with breast cancer, the painful effects of its treatment, and the expectation to perform unceasing gratitude toward the evangelical community that reluctantly supports her out of a transactional sense of duty. Jane's eldest son, Dalton, has been discharged from the army under conditions "Other than Honorable." Accused of breaching the military's Don't Ask, Don't Tell policy, Dalton drifts hesitantly home, pulled by guilt and love for his younger brother. Messy (christened Messiah at Grace's insistence) is awkward in a world that attacks difference. Guided by faith, tortured by abandonment, Messy eventually develops a warped moral code shaped by alienation and anger.