In deep winter, early February 1887, two brothers, John and Lafayette Lodi, flee Kentucky in the middle of the night, heading west toward Indian Territory. The men carry their families with them in covered wagons, and - hidden between them - a corrosive rivalry born of the inescapable bond of blood. John, tortoise-stubborn, is a master gunsmith; Fayette is jealous, grasping, a mule thief and bootlegger. Between the brothers, an ancient tragedy threatens to play itself out.

Thus opens The Mercy Seat, an unblinking, keen-eyed vision of the settling of the American West, told first by Mattie, the ten-year-old daughter of John Lodi, and echoed in the voices of the white townspeople who migrate into the Indian lands. Set in the harsh and beautiful Ouachita Mountains of southeastern Oklahoma, the novel follows Matt as she struggles to hold her disintegrating family together with a mix of spite, loyalty, and fierce will.

When Mattie is struck down by fever, a Choctaw healer brought in to pull the girl back from the territory of the dead recognizes in her a powerful gift of visions. But Matt turns away even from this imperative call in her desperation to restore her family to their home back East. As the bitter conflict mounts between John and Fayette, so does the war between her visions and her will - and in the final, unavoidable clash, Matt will hold both mercy and destruction in her hands.