John Parsons is an orphaned teenager living on a ranch as a tenant rancher in rural New Mexico, cared for by his 19-year-old brother Chris. John is smart enough for college, with Chris harboring a dream for him to become a veterinarian.
One day, Chris allows John to help him round up a herd of horses for their boss, ranch owner Bea Saunders, as payment for Friday, a horse Chris bought from her to give to John. As they're attempting to break one of the last horses, something goes wrong and Chris suddenly dies.
Bea shows no compassion for John, refusing to let him stay on the cabin he and Chris shared on her land, and letting Chris be buried in a pauper's field. Reacting angrily to Bea, John returns to the cabin and smashes a kerosene lamp on the kitchen table to the floor, engulfing the cabin in flames and causing it to be burned to the ground.
He attempts to escape on Friday, but is quickly apprehended by the sheriff. Because of the crimes against him, he cannot be placed in foster care, nor can he be placed in the custody of unlicensed foster parents willing to care for him, forcing a judge to commit him to a juvenile detention center until his 18th birthday.
Despite the sanitized name of Sierra Mesa Industrial School for Boys, it's little more than young offenders in a prison environment, with inmates as young as six and as old as 20, who are treated no better than adult prisoners. An idealistic new superintendent at Sierra Mesa and another teacher see John's potential and push for him to do better, but John slowly begins to lose hope for his future, and their attempts to change the system are rebuffed at every turn.
Risking their own lives and careers, the pair formulates a plan to bring justice for John.