The novel starts with a prologue in which the main character and narrator, David, thinks back to the year 1948 and the events that influenced his life. David thinks about his parents and the year he saw his father on the floor, crying, and his mother by the window, holding a gun in her hands. David also remembers a young Native American woman, lying in bed and coughing, a clear indication that she was going to die. Then, David tells the reader that he will be discussing the three people he mentioned, people who died a long time ago, and tell their stories even though there was no one left alive who loved them.
In the first chapter, David describes the town where he lived with his parents in 1948. 1948 Bentrock, Montana is a small town near a Native American reservation. The people there have a harsh life, and they have to endure poverty and a harsh climate all year round. Despite this, David feels happy and protected. David’s father, Wesley, is among the only men who did not go to war because of his leg and serves as the sheriff of the little town. Wesley’s wife and David’s mother, Gail, is somewhat dissatisfied with her husband because she feels they could have a better life if Wesley were to practice law and become a lawyer instead of being a small town sheriff. Wesley agreed to become Mercer County’s sheriff out of duty to his own father, who was once also sheriff and wanted his son to follow in his footsteps. Gail wants to move from the little town but her husband refuses because his family is highly respected and valued in Bentrock. Gail also works, so David is looked after by a Native American woman named Marie Little Soldier.
One day, Marie gets sick and Gail does everything she can to help, despite Marie’s protests. Marie insists that she doesn’t need a doctor and even makes David promise her not to let Uncle Frank, the doctor who also happens to be Wesley’s older brother, come near her. When David’s parents come back home, they refuse to acknowledge Marie’s fears and insist that she should see a doctor to treat her worsening fever.
When Uncle Frank arrives, David notes how Uncle Frank appears to be everything his father is not, and even mentions that his Grandpa Hayden sometimes talked as if he only had one son, Frank. When Frank enters Marie’s room, she starts screaming for Gail, who rushes to her aid. Marie continues screaming and when Frank comes out he tells the family that she might have pneumonia. Frank leaves when he sees Gail, and David notices that his mother is not happy. When he is told to go inside, David eavesdrops on his parents’ conversation. He discovers Gail is unhappy because Marie told her that Frank has been molesting Native American women. Gail tells her husband that Frank has even raped Native women but Wesley doesn’t want to hear it. Gail and Wesley go to talk with Marie but Wesley is more concerned about the way his grandfather will act than the well-being of the Native American women.
The next day, Wesley goes to investigate the allegations against Frank. When he returns home, he insists on speaking alone with Marie about Frank, and thus Gail takes David outside. That weekend, the family decides to go and visit Grandpa and Grandma Hayden even though Gail expresses her desire to stay at home. At Grandpa Hayden’s home, Julian makes allusions to Frank’s behavior and possible offspring he may have fathered with Native American women. It is also implied that his behavior was nothing new and that it presented itself even before Frank got married. This makes David question whether his grandfather will care about Frank’s crimes.
David goes outside after he finishes dinner and plays with his grandfather’s gun, shooting birds from nearby trees. On the car drive home, David overhears his mother and father talking about Frank, with Wesley claiming that the problem is now solved. Gail is not so sure however, and says that Frank has to be punished for his crimes.
When the family returns home, they find Marie sitting with another Native woman, in a better condition than they expected her to be. The next day however, Marie dies suddenly and David is told to go and stay with a neighbor while his parents process her death. David goes and stays with Len, the sheriff’s deputy and the two talk briefly. David notices that Len, a recovering alcoholic, is drinking again, hinting that something is bothering him.
That night, David tells his father that he saw Frank enter the house before Marie died. This information alarms his parents, and Wesley reopens his investigation into Frank.
Marie’s body is taken from the house but the Haydens don’t attend the funeral because Marie’s family decides to bury her in North Dakota. Later that week, Wesley asks Frank to come to his house and they talk in the basement, a place where they can’t be heard. When Wesley comes back upstairs, he is alone. When Gail comes home, Wesley tells her that he arrested Frank and is keeping him in the basement for now. That night, Wesley’s parents comes to the house, demanding that Wesley let Frank go. When Wesley tells his parents that Frank sexually assaulted Native American women and murdered Marie, his parents are shocked.
When David goes downstairs, he finds his father crying. Wesley tells David that if his grandparents ever come to the house again, he is not to let them in. When David goes to buy groceries the next day, he can't stop thinking about the girls his uncle molested every time he passes a woman on the streets.
Later that day, David sees a truck circling their house and recognizes the men in the truck as Grandpa Hayden’s employees. One of the men has an axe so Gail runs to get her husband’s gun while also sending David to get help. David runs to his father’s office but only finds his father’s secretary so he returns home. As he goes home, he hears his mother fire a warning shot at the men and order them to leave her property. A few moments later Len, also armed, approaches the house and gets the men to leave. While Gail hugs Len and thanks him, Wesley finally arrives home. He tells them that Frank will be charged for sexual assault, and ensures that Len will be home whenever he is away.
Gail tries to convince Wesley to let Frank go because she is tired of the danger and drama Frank’s case is causing. However, Wesley decides against letting his brother go, because Frank shows no remorse for his actions. He decides to take Frank to the town jail the next morning.
The next morning, Wesley finds Frank dead in the basement because he slit his own wrists with a shard of glass from a jar.
In the epilogue, David recalls the events that happened after Frank killed himself. The Haydens hid Frank’s suicide and said his death was an accident. Grandpa Hayden never spoke to them again, and David and his parents moved in December to North Dakota. Wesley became a successful partner at law firm and David grew up to become a beloved history teacher. David got married and has a happy life, but he is able to see how the secrets surrounding Frank’s death affected his family. Still, from those outside the family, the story is an intriguing one that seemingly embodies the spirit of the Wild West.