Billy is a sixteen-year-old boy living with his family on a ranch in Hidalgo County, New Mexico. Eager to prove himself, he adopts his father's stoic, methodical approach to ranching and trapping. His strong, somewhat naive sense of justice drives him to take independent action when a pregnant wolf appears on their land. He is determined to right the wrongs he perceives in the world, often leading him into situations entirely beyond his understanding.

Boyd is Billy's fourteen-year-old brother, who often feels overshadowed by Billy's standing in the family. He is sensitive, sometimes sullen, and eager to prove his worth after a mishap damages his saddle. He holds a romantic view of the world and acts boldly to assert his own agency, frequently chafing under his brother's authority.

A pregnant wolf that travels from Sonora into New Mexico seeking food and safety. Driven by survival instincts, she outsmarts several traps before finally being caught. She represents the chaotic, untamed natural world that exists entirely outside the rules of human civilization.

A hardworking rancher trying to scratch out a living in the Animas Valley. He teaches Billy the precise, methodical skills of wolf trapping and trusts his older son with adult responsibilities, though he sometimes overlooks Boyd's need for validation.

A practical and religious woman living on the Parham ranch. She provides moral grounding for the family, enforcing domestic routines and religious observance on the frontier.

A neighbor of the Parhams who owns the SK Bar ranch. He helps the family by providing access to the old wolf traps left behind by a former hunter, representing the cooperative nature of early frontier communities.

A wandering man who demands food and rifle shells from the Parham boys. He harbors resentment toward the settlers for disrupting his hunting grounds and questions the boys in a threatening manner, representing the unresolved cultural tensions of the region.

An old, ailing former hunter in the Animas Valley. He speaks philosophically about the natural world and tries to warn Billy that capturing a wild animal is a foolish endeavor, arguing that to catch a wolf is to lose it.

A distant relative of Don Arnulfo who cares for the sick old man in his isolation. She warns Billy to stay connected to humanity lest he end up ostracized and accused of witchcraft like Arnulfo.

A bailiff or constable in a Mexican town near the Batopito River. He operates under the authority of the local power structures and casually exercises control over outsiders, enforcing his will without concern for Billy's intentions.

The son of a wealthy hacienda owner in Mexico. He defends his community's actions by accusing American outsiders of trespassing and disrespecting Mexican laws, pointing out the hypocrisy in Billy's righteous quest.

A hospitable former priest living in a collapsed church filled with cats. He shares a long, philosophical story about a heretic to impart a lesson about the importance of living for others and finding meaning in shared narratives.

A fourteen-year-old Mexican woman rescued by the Parham brothers. She remains traumatized and initially mute, eventually deciding to travel with the boys. Her presence complicates the brothers' dynamic as she forms a distinct bond with Boyd.

A confident judge of character who purchases horses at auction. He advises the Parham brothers to return home rather than challenge the powerful Hearst estate, recognizing the boys' dangerous idealism.

An aggressive rider working for the Hearst ranch. He challenges the boys over a herd of horses and is willing to use intimidation and violence to assert his employer's claims over the property.

A reasonable, authoritative man connected to the local power structure in Mexico. He listens to the boys' story and issues them a writ of safe passage, demonstrating a complex personal code of honor amidst a lawless environment.

An actress traveling with an opera company through Mexico. She views the world with a sense of jaded boredom, believing that life is merely a performance masking an empty reality.

A veteran of the Mexican Revolution who was brutally blinded by a captor. Despite his trauma, he shares a deeply philosophical story about finding meaning, community, and acceptance in a violent, impermanent world.

A supportive and articulate woman who helps her blind husband recount his history. She demonstrates the power of shared narrative and community, acting as the voice for her husband's deepest truths.

A skilled and generous medical professional operating in Casas Grandes. He performs painful but life-saving procedures out of a pure sense of duty, refusing to accept payment from those in desperate need.

A fiercely patriotic veteran of the Mexican Revolution. Intoxicated and combative, he strongly objects to American arrogance and is quick to show the physical scars he earned fighting for his country.

The philosophical head of a group of wandering muleteers. He helps treat an injured horse and shares stories about the futility of seeking permanence, advocating for an optimistic acceptance of life's unpredictable nature.