Chas McPherson and his father are shepherds–one of beasts, the other of souls. The hard-crusted, hard-drinking younger McPherson, a misunderstood loner, raises a breed of sheep known as Blackbellies. The father, dying of Parkinson’s, is tendd by a newly hired nurse with a past, Mattie Holden. The father had been a fire-and-brimstone pator whose uncanny ability to detect and then reveal the townspeople’s sins kept them in dread of him. When the home of Sweetwater’s lone Muslim family is burned to the ground, those past fears and grudges contribute to the town turning against the younger McPherson as the suspected arsonist.

Sheriff Kip Edelson methodicaly and conscientiously investigates the arson accusation, and a subsequent one of murder. At the McPherson ranch, Mattie is haunted by a sense that the incapacitated, now-mute father can see into the secrets of her own past. She and Chas draw closer together as mutual emotional needs slowly replace inital antipathy. Surprising developments in town and at the ranch gradually bring them to a reckoning with the once-fierce father and to a journey to forgivness.