Saul Indian Horse is a member of the Fish Clan, an indigenous tribe from northern Ontario. He grows up with his parents, John and Mary; his brother Benjamin; his sister Rachel; and his grandmother, Naomi, in the late 1950s. For years, white Canadians had been kidnapping native children and bringing them to Christian schools to “remove the Indian” from them. Benjamin and Rachel are kidnapped while young children. Mary never recovers. John and Mary, who were put through Christian schools themselves, try to teach English to Saul, while Naomi attempts to keep their clan’s traditions alive. Miraculously, Benjamin appears one day, having escaped school. Naomi decides the family must move further north, to God’s Lake, where their ancestors are from. Naomi tells the family that they need to go there to heal, especially Benjamin, who now suffers tuberculosis, which he caught while at school.
The family learns to harvest rice in God’s Lake, and for a time, they live in peace. While there, Saul experiences a vision of his ancestors and the tragedies they endured at God’s Lake. Benjamin’s body, weakened from tuberculosis and labor, gives out. Mary becomes bitter and resentful, torn between Naomi’s insistence on following Fish Clan traditions and her own Christian education. She insists that the family go back to town, where Benjamin can get a proper burial with a priest. The family leaves, abandoning Naomi and Saul. When autumn arrives, Naomi realizes they will freeze if they remain in God’s Lake without proper supplies. She packs their canoe and she and Saul head to Minaki, where she has a relative. Naomi and Saul endure heavy snow and freezing winds. They make it to the train tracks, where a group of men find Saul, embraced by Naomi’s frozen corpse.
Saul is taken to St. Jerome’s, a place where indigenous children are stripped of their culture and made Christian. He experiences and witnesses countless acts of horrific abuse. The nuns and priests beat the children, imprison them, and even molest and rape them at night. Many of the children don’t survive. They get killed, die from punishment and neglect, and commit suicide. Saul retreats, finding solace in books. When Father Gaston Leboutilier, a young cheerful priest comes to the school, Saul believes he has found a new ally and friend. Leboutilier builds a hockey team at the school. Saul becomes obsessed with the game and asks to play but is too young. Instead, Leboutilier gives Saul a job cleaning the ice. Saul rises early in the morning to practice and builds his skills until he becomes old enough to play. Soon, people recognize Saul’s talent. Saul is thrilled he has found something that completely absorbs him and relieves his pain.
Saul’s skills grow with his enormous discipline and practice. A former St. Jerome’s student, Fred Kelly, comes one day to offer to adopt Saul and give him a chance to play on his local team, the Moose. The Moose play in an indigenous league. Saul feels delighted yet partly sad to leave the familiarity of St. Jerome’s behind. Living with the Kelly family, Saul finds comfort and safety. He becomes close with Fred’s son, Virgil, who also plays hockey. Saul becomes a star player on the Moose team. He learns what it is to play in tournaments and have camaraderie with teammates. Soon, Saul’s talent is recognized by town teams, who challenge the Moose to play against them. Saul leads the Moose to more and more wins, though they suffer racism and abuse from the town teams and fans along the way.
Eventually Saul captures the attention of an NHL scout, who invites Saul to try out for a feeder team for the Maple Leafs in Toronto. Reluctant to face more abuse, Saul hesitates, but Virgil convinces him to take the chance. Saul makes it onto the rookie team but endures brutal racism. The press calls him an “Injun” and “savage.” Saul tries to restrain himself, to keep the game pure and sacred for himself, but he soon becomes overwhelmed and lashes out, brutally attacking other players who come at him. He returns to the Kellys’, feeling resigned and defeated. Back home, Saul finds work on a forestry crew, but the white workers insult and harass him. When he almost strangles one to death, Saul decides it’s time to leave. He packs up his truck and heads south. He works all sorts of manual jobs for a time, finding solace in drinking and becoming the town “Injun” wherever he goes. Erv Sift, a farmer, tries to help Saul by giving him steady work and a place to live. Sift tries to wean Saul off alcohol, but Saul relapses. Embarrassed and guilty, Saul leaves Sift without telling him.
Eventually, Saul finds himself in the hospital from drinking. The social workers send him to the New Dawn Centre, a treatment facility. There, counselors encourage Saul to tell his story, but Saul finds the task too overwhelming. He explores the grounds instead. While surrounded by nature, Saul has a vision of his great-grandfather and realizes he must go back to St. Jerome’s, which is now abandoned. While at St. Jerome’s, Saul recalls his time there and realizes that Leboutilier sexually abused him the whole time.
Anguished, Saul heads to God’s Lake, where he has another vision. In this vision, his great-grandfather tells Saul that he has come here to learn how to live with God’s Lake in his heart. Saul realizes he must heal his pain to live his life. He reunites with the Kellys and Virgil, opens up about all he’s been through, and slowly begins to build a new life.