The Parham family moves to Hidalgo County in New Mexico in the years before World War II. One night in their first year in their home, protagonist Billy Parham heads out alone to track wolves as they hunt antelope. Years later, Billy, now 16, gathers wood with his 14-year-old brother Boyd. They encounter an Indigenous man who chides them for scaring animals away. He demands they feed him, and Billy agrees to bring some food to a spot the Indigenous man indicates.

When the boys bring the man food that night, he asks questions about their belongings and demands they give him rifle shells to trade, but they refuse. Billy agrees to bring him coffee, and the boys depart, leaving a cup with the Indigenous man. Billy admits to Boyd that they won’t be returning with anything.

In the morning, Billy rides out on his horse Bird to the man’s camp and finds him gone. Billy’s father returns home and reveals that there’s a female wolf loose on their land. He believes it came from Mexico, and he tells Billy they need to catch it.

Billy, Boyd, and their father ride out to the SK Bar ranch, where their neighbor Sanders lets them into a cabin on his land that a hunter, Echols, used to live in.