In the ruined Grimholt fortress, Orka wakes from a nightmare about her son’s abduction. She is surrounded by sleeping Bloodsworn mercenaries, exhausted after the battle in which they took the fortress, which had belonged to the ruthless, expansionist Queen Helka. Lif, one of the brothers she freed, startles her, and she nearly kills him. After washing the battle’s gore from her body in a river, she is confronted by Lif. She admits she is “Tainted” with the blood of the wolf-god Ulfrir, as is her son Breca, and confirms her past identity as the “Skullsplitter,” former chief of the Bloodsworn. Lif asks for help burying his brother Mord, killed while in chains by the warrior Guðvarr, and they retrieve his charred, chained corpse from the tower. She is met by Svik, a Bloodsworn warrior who expresses hurt at her past abandonment. Glornir, the Bloodsworn chief, reveals that their resident Seiðr-witch, Vol, was abducted by Skalk, a Galdurman, or magician, sent by Queen Helka to pursue the Bloodsworn. Orka confirms that Skalk escaped on a boat. As they talk, the tennúr Vesli—a magical, winged creature capable of mystical visions—awakens from a dream, screaming that the dragon-god Lik-Rifa has been freed, a fact confirmed by her companion, Spert.

The remaining members of the Battle-Grim build a funeral cairn for their slain chief, Agnar, on the ash-covered plain of Oskutreð. The Seiðr-witch Uspa reminds Elvar of their binding blood oath to retrieve her son, Bjarn. When Elvar and another warrior, Sighvat, contemplate abandoning the quest, the magical oath burns their arms, proving that it cannot be broken. Elvar strategically allows the looting of the plain to continue, reasoning that the Battle-Grim will only agree to join the quest against Lik-Rifa once they are sated with silver. They find several valuable relics. Suddenly, their winged captive, one of Lik-Rifa’s former gaolers, or jailers, awakens, breaks her leather bonds, and attacks. Using her knowledge of binding spells, Elvar forces a thrall-collar onto the woman, enslaving her. The woman reveals that her name is Skuld and learns that her sisters died fighting Lik-Rifa. The fighters demand to know where the treasure is; reluctantly, Skuld tells them that the best treasures lie in the caverns below.

Varg helps Orka and the Bloodsworn bury Mord. During the task, he and Lif bond over their lost siblings. Orka’s former comrade Røkia confronts her about abandoning her oath to the Bloodsworn. Later, Glornir asks Orka how his brother Thorkel, Orka’s husband, died. She recounts the attack and reveals that the killer, Drekr, is a dragon-born. She shows them the distinctive seaxes Drekr left behind. Varg recognizes the unique knotwork; it matches the seax he took from the dragon-born he killed at the mine. They conclude that the events are connected. Recalling the battle at the Grimholt, Orka confirms that Skalk the Galdurman was wounded and fled downriver toward Darl, where Queen Helka reigns. Glornir declares that the Bloodsworn will go to Darl to rescue Vol.

The enslaved demigod Skuld—who reveals that she is the daughter of the wolf god Ulfrir and the eagle goddess Orna—guides Elvar and a party of Battle-Grim deep into the caverns beneath Oskutreð. Though Skuld is far more powerful than any of the humans, the thrall-collar around her neck forces her to obey Elvar’s commands. Still, Elvar worries that she won’t be able to control Skuld. As they descend a long, spiraling path, Elvar explains to Skuld that the world has changed: The gods fought a war that almost destroyed humanity, and now the remaining gods and their descendants—called the “Tainted”—are despised and enslaved. They enter a massive chamber that was once the home of Skuld and her two sisters during their long vigil guarding Lik-Rifa. The group moves deeper into a foul-smelling cavern, Vergelmir, which was Lik-Rifa’s prison. There, they witness the “soul road”—a grim procession of the spirits of the dead, which Lik-Rifa apparently fed upon. At the far end of the chamber, they discover a black book on a pedestal, protected by a glowing rune-circle. Skuld suggests that the book likely belonged to Lik-Rifa, but she doesn’t know its purpose. When a warrior named Huld steps past the runes, a magical blast throws everyone back and extinguishes their torches as monstrous creatures attack from the darkness.

Biórr is welcomed back into the Raven-Feeders by their chief, Ilska. He has spent the past three years as a spy among the Battle-Grim, and he was the one responsible for freeing Lik-Rifa and killing Agnar, the leader of the Battle-Grim. Thanks to him, the Raven-Feeders now know the location of Oskutreð, the underground system of caverns that housed Lik-Rifa. He reunites with his former lover, Myrk, but feels detached after his time away. Despite the adulation of his comrades, he feels guilty for killing the great warrior Agnar in such a duplicitous way. He finds Kráka and Ilmur, now free, sitting among a large group of Tainted children who are all enslaved with thrall-collars and kept docile by a spell. Kráka and Ilmur were enslaved to the Battle-Grim before Biórr freed them. The Raven-Feeders’ purpose is to free all the Tainted, and Biórr finds the continued enslavement of the other children hypocritical, but Myrk frames it as a temporary necessity—once the children have adopted the Raven-Feeders’ cause, they will be freed. Ilska dispatches Myrk to retrieve treasures from another location. After a brief sexual encounter with Biórr, Myrk departs with her warriors.

The Battle-Grim fight for their lives against a swarm of monsters in Lik-Rifa’s dark chamber. Elvar commands Skuld to join the battle. As they are being overwhelmed, the Seiðr-witch Uspa unleashes a powerful light spell, driving the creatures back. Uspa then dispels the protective runes around the book on the pedestal. Elvar punishes Skuld for leading them into the trap. Uspa reveals that the book is a Galdrabok—a spellbook—written by Lik-Rifa, which contains a spell for resurrection. Skuld begs them to use the book to resurrect her father, the wolf-god Ulfrir, to defeat Lik-Rifa. Seeing it as the only way to fulfill their blood oath and save themselves, Elvar agrees. She rallies the other Battle-Grim by appealing to the glory they will win by slaying a god.

Orka prepares to leave the Grimholt. The Bloodsworn chief, Glornir, asks her to rejoin their warband, but she refuses, stating that finding her son Breca is now her only purpose. She tells Glornir she will travel to the mine where his crew fought a dragon-born to search for clues. Glornir assigns his scout, Edel, and a small retinue to guide her. Orka arranges for Glornir to take the rescued Tainted children and Lif with him to Darl. Lif, however, insists on staying with Orka to continue his combat training so he can one day avenge his brother. Orka reluctantly agrees. The Bloodsworn depart for Darl, while Orka, Lif, and Edel’s party head west toward the mine.

The Battle-Grim prepare to resurrect the wolf-god Ulfrir. In the forge within Oskutreð’s caverns, Uspa uses Lik-Rifa’s Galdrabok to forge a thrall-collar powerful enough to bind a god. The group then emerges to the surface, where Uspa performs the resurrection ritual over Ulfrir’s skeleton. She directs the other warriors to offer their blood, which she uses to power the spell. As she chants, flesh, muscle, and fur grow over the massive skeleton of Ulfrir. The giant wolf is reborn, but he is still covered in the many wounds that originally killed him. After letting out a fearsome howl, the wolf collapses from weakness and exhaustion. His body then transforms and shrinks into the shape of a severely wounded man. Skuld rushes to his side, and the reborn god asks after his mate Orna and his other daughters before learning that they are all dead.

Biórr tries to settle back in with his old Raven-Feeder comrades, but their reunion is interrupted when Lik-Rifa, in human form and now in command of the Raven-Feeders, awakens from a nightmare, screaming that her brother, the wolf-god Ulfrir, is alive. When her second-in-command, Ilska, questions this, Lik-Rifa flies into a rage, transforms into her dragon form, and eats one of her own guards. She nearly attacks Ilska before Drekr, Ilska’s brother, stands between them. Calming down, Lik-Rifa transforms back into a woman. She insists she is right about Ulfrir’s return, having sensed the use of her stolen Galdrabok. She orders the entire warband to march south with all speed.

Orka’s traveling party is ambushed by night-hags while they sleep. Awakened by her heightened wolf-senses, Orka discovers that Lif, who was on watch, has fallen asleep and is being slowly strangled by one of the creatures. Orka’s first axe-swing passes through the hag harmlessly; only by speaking the Seiðr-words Uspa taught her while striking does she succeed, killing the creature and saving Lif’s life. The next morning, Edel confronts Orka, calling Lif a dangerous liability whose carelessness could have gotten them all killed. She suggests that Lif’s knowledge of their Tainted nature makes him a threat to the Bloodsworn’s secrecy. Orka acknowledges Lif’s failure but declares that he is in her debt and under her protection, refusing to abandon him.

Varg continues his pre-dawn combat training with Røkia as the Bloodsworn travel south. She easily bests him, and he complains that his new helmet fits poorly. To fix it, Røkia briefly manifests her Tainted hound-like teeth to bite a new hole in the leather strap. She and another warrior, Svik, advise Varg that he must learn to master the wolf-spirit within him, letting its power flow in a controlled manner rather than being consumed by its rage. Meanwhile, their chief, Glornir, remains grim and focused on rescuing Vol, the Bloodsworn’s kidnapped Seiðr-witch, and orders the group to prepare to move out.

Guðvarr, the warrior who slew Lif’s brother Mord, is on a crowded boat fleeing the Grimholt massacre and rowing downriver to Darl. He feels ashamed for having run from Orka but justifies his cowardice by noting that even Skalk the Galdurman also fled. Annoyed by a gravely wounded warrior still clinging to life, Guðvarr steals the man’s silver eagle-winged brooch before falsely declaring him dead and having him thrown overboard while his eyes still flutter. Also on the boat are Skalk and the captive Vol. Skalk taunts Vol, who retorts that the Bloodsworn will hunt him down for stealing from them. She observes that Skalk’s power is diminished now that he is wounded and has lost his staff. As they near Darl, Guðvarr is filled with dread at the thought of facing his aunt, Jarl Sigrún, after failing his mission to kill Orka.