Xavier is a young Cree man raised in the Canadian bush who enlists in the Canadian army alongside his childhood friend to fight in Europe. Deeply rooted in the traditional ways taught by his aunt, he views the war with a solemn, respectful eye toward life and death. He returns home suffering from a severe physical injury and a heavy addiction to morphine. He communicates very little in English, which isolates him from many of his fellow soldiers.

Niska is an older bush Indian who lives away from modernized towns. She operates as a traditional healer and seer. She carries the heavy responsibility of being a "windigo killer," a role passed down from her father to protect their people from cannibalistic madness. She embarks on a three-day canoe journey to bring her wounded nephew home, using stories of her past to keep him tethered to life.

Elijah is Xavier's childhood best friend, an outgoing and charming Cree youth. In the army, he adapts quickly to military culture. He speaks with a British accent and expresses comfort with the act of killing. He enjoys the praise of his peers for his exceptional marksmanship, drawing energy from the chaos of the battlefield.

McCaan is the commanding officer of Xavier and Elijah's platoon. He takes his responsibility seriously and feels frustrated by the poorly planned orders he receives from higher-ups. He acts as a steadying presence for the young soldiers as they face the horrors of the trenches.

Corporal Thompson is a seasoned veteran who teaches the new arrivals how to survive in the trenches. He takes a special interest in Xavier and Elijah, instructing the young men on crater navigation, barbed wire hazards, and the mechanics of sniping in no man's land.

Lieutenant Breech is an arrogant commanding officer whom the men secretly call "Bastard Breech." He quickly develops a strong prejudice against Xavier, misinterpreting the young Cree man's limited English and quiet demeanor as insubordination. He frequently organizes dangerous raids that put the men at unnecessary risk.

Grey Eyes is an American soldier serving in the Canadian battalion. He sustains a heavy addiction to morphine, which causes him to be careless on duty and puts his fellow soldiers at risk. He serves as the primary source of the drug for others in the unit.

Sean Patrick is a very young soldier, only fifteen years old, serving in Xavier and Elijah's platoon. He talks constantly to calm his nerves and proves to be a promising marksman, though his youth makes him vulnerable on the battlefield.

Fat is a fellow soldier in Xavier and Elijah's platoon. He experiences the confusion and terror of navigating the dark and muddy battlefields alongside the main characters, trying to survive the daily hazards of trench life.

Gilberto is a cautious soldier in the battalion who prefers not to take unnecessary chances. He frequently thinks of his wife back home and relies on Elijah to help him draft fanciful letters detailing military exploits he did not actually perform.

Niska's father is a great storyteller, seer, and traditional windigo killer. He leads his people through brutal winters and starvation, carrying the heavy burden of eliminating those who turn to cannibalism to protect the larger community.

Niska's mother is a traditional bush Indian who tries to keep her family together after her husband is taken away by white authorities. She rescues a young Niska from a harsh residential school and teaches her the ways of the shaking tent.

Rabbit is Niska's sister and Xavier's biological mother. Unlike Niska, she chooses to live as a "homeguard Indian," adopting white customs and ultimately giving her son over to the care of the residential school nuns.

Sister Magdalene is a strict nun at the residential school where Xavier and Elijah are sent as children. She participates in the institutional effort to strip the Indian children of their culture, language, and traditional beliefs.