The final installment of
The Reckoner trilogy is set in Wounded Sky First Nation, a remote Cree community in northern Manitoba. In the previous books, teenager Cole Harper discovered that Mihko Laboratories, a corporation with a facility on the reserve, had been experimenting on him; his father had secretly used Cole to develop a cure for a virus Mihko was weaponizing. Cole believed his superhuman strength and speed came from a childhood bargain with Choch, a trickster spirit in coyote form, and bore palm scars from gripping the burning door handles of his school at age seven to rescue classmates. Cole learned that Reynold McCabe, the community's chief, had become Upayokwitigo, a cannibalistic ice giant from Cree tradition. He confronted and shot Reynold but was killed himself, shot in the head by an unidentified figure in a hazmat suit.
The novel opens immediately after Cole's death. Reynold stumbles home wounded, and his daughter Lucy discovers his blood runs blue and ice-cold, evidence of his transformation. A figure in a hazmat suit confirms an unnamed task is done.
A month later, Eva Kirkness, Cole's closest friend and love interest, lives under Mihko's quarantine: Cell service is cut, no one may leave, and food is rationed. Mihko has framed Cole as an arsonist and murderer. Eva recalls that Choch appeared at Cole's grave and offered to bring him back in exchange for an unspecified future favor; she agreed, but the spirit has not returned. One evening, a community member named Tristan reports a shambling figure in the community. Eva suspects Cole is no longer in his grave.
A decomposed creature staggers through Blackwood Forest, the dense woodland surrounding the community, killing two Mihko guards before reaching a cabin where Elder Mariah, a respected healer, lives with her grandson Brady, Cole's best friend. Elder Mariah recognizes the figure and whispers, "Cole…You've come a long way" (20). She applies traditional medicine to his body, and his supernatural healing gradually restores him. Jayne, the ghost of a seven-year-old girl who died in the school fire, visits him. Half her body perpetually burns, and she is stuck on Earth until Cole finishes his task, having guided his spirit back from the northern lights, the afterlife in Cree tradition. Cole promises to get her home.
Brady reports that Mihko has locked down the community and roughly eight people have gone missing. Cole resolves to return under a disguise, adopting the codename from Mihko's files: The Reckoner. He and Brady hike back, neutralize a perimeter guard, and set up at a vacant trailer. They recruit allies: Eva, Dr. Captain, and Lauren. Dr. Captain is a local doctor and the mother of Michael, Eva's ex-boyfriend. Lauren is Jayne's older sister and an officer with the Royal Canadian Mounted Police (RCMP), Canada's federal police force. Cole infiltrates the clinic and finds patients gravely ill and unconscious, including Eva's father Wayne and his missing friend Pam. He retrieves Pam's medical chart and brings it to Dr. Captain.
At the cemetery, Eva waits at Cole's grave. She recognizes him despite the disguise, knowing about his return through her deal with Choch. She reveals she filled in the hole he left when he dug out of his coffin. When Cole describes the illness at the clinic, Eva insists they act that night.
Cole goes to Reynold's fortified house to retrieve experiment files. Choch reveals a devastating truth: Cole always had his superhuman abilities. As a seven-year-old, he broke the school's chained doors with his bare hands; Choch only made him believe the powers came from their bargain, giving him the confidence to use them. The only genuine gift was accelerated healing. Cole is enraged but chooses to stay and fight. He battles through armed guards and retrieves the files, but Upayokwitigo appears as a towering ice giant. The monster throws Cole across the room into Lucy, who followed him upstairs, killing her on impact. Cole flees. Outside, Choch transforms into a half-man, half-coyote beast to buy time, but the monster rips out Choch's heart. The spirit being dies in Cole's arms, his body fading away.
Tristan carries the wounded Cole to the trailer, where the team has assembled, including Michael, who comes as a package deal with his mother. Dr. Captain examines the files and determines that Mihko has been developing a biological weapon using community members as test subjects. Cole's blood carries the cure. The team raids the clinic that night. Cole and Lauren assault the guards while Jayne, at Cole's request, sets guards on fire, an act that devastates her. They evacuate patients onto boats, but a Mihko guard fatally shoots Tristan during the escape.
They deliver patients to Elder Mariah's cabin, where a tent city is established. Cole and Lauren drive the boats downriver to create a false trail, then walk back. Cole tells Lauren about Jayne's spirit, and Lauren weeps with relief. Choch appears one last time as a translucent ghost, encouraging Cole to finish the job, then fades permanently.
The next morning, Brady and Michael are missing. Mihko coerced Michael by threatening his mother's life, and he has delivered Brady to the facility. Cole and Eva set out together. Near the perimeter, a guard shoots Cole and seizes Eva at gunpoint. As the guard counts down, Eva screams, and a rush of wind lifts them both into the air. The guard falls to his death; Eva floats gently down, having manifested powers tied to her deal with Choch. At the facility, Cameron Xavier, Mihko's representative, ambushes and captures them.
Cole wakes strapped to a bed in the facility basement. Eva and Brady lie nearby, infected with a new virus strain; Mihko is extracting Cole's blood to develop a cure, using his friends as test subjects. Xavier reveals that Reynold set the school fire ten years ago to kill Cole because Cole's father had been helping Vikki, Reynold's girlfriend, escape rather than having an affair with her. Xavier also reveals that Michael was the figure in the hazmat suit who shot Cole, acting under duress. Once the cure is confirmed, Reynold will be released to kill them all.
Eva and Brady wake, cured. Michael frees Cole and stays behind with grenades to hold off Reynold, asking Cole to protect his mother. Cole escapes with Eva and Brady, then returns for Michael. Michael seals the basement doors, trapping himself with the monster, and pulls the pins on two grenades. Cole shares a final look with Michael through the glass and runs. The explosion destroys the facility.
From the flames, Jayne emerges carrying Michael, having shielded him with wings of fire. Michael hands Cole an icicle threaded with blue veins: Reynold's heart. At the ruins of the elementary school, Cole picks up a chain link from the old door chains, and the scar on one palm disappears; he keeps the other. Jayne's flames lift away as embers until she stands whole and unburned, visible to everyone for the first time. She ascends to the northern lights. Cole and Eva kiss. He tells her he is home.
Weeks later, Cole and Eva drive out of Wounded Sky in a repaired Mustang. An RCMP officer pulls them over, speaking in movie references and calling Eva "Captain Kirk." It is Choch, alive in some new form, hinting he may need them again. The novel closes: "The Reckoner will return."