Emilia once again finds herself chained in the stone chamber in the Shadow Realm with Domenico. He taunts her while they wait for Vittoria, who soon arrives dragging a badly beaten Nonna Maria. When Emilia struggles against her chains, Nonna cringes away and prays for divine protection from her granddaughters. Vittoria reveals that she caught Nonna hexing the gates to trap Emilia in the Seven Circles.

Nonna coldly justifies the coven’s actions as wartime sacrifice, admitting that they murdered two infants for their hearts to create the spell-locks on the twins. At Vittoria’s command, she confesses to trapping Sofia Santorini’s mind for nearly two decades after Sofia discovered coven secrets. Vittoria forces her to reveal the full story: The First Witch cursed Wrath and then schemed with House Vengeance to pit Wrath and Pride against each other to reclaim her daughter, who was Pride’s wife.

Memories return to Emilia: She and Vittoria were sent to seduce Wrath and Pride, but Emilia fell in love with Wrath and foiled the scheme. They were about to escape together when Emilia was attacked and taken. Vittoria explains that the prophecy of twin witches referred to two infants that the coven sacrificed that night, using their hearts to create the spell-locks and infuse mortality into the twin goddesses. The witches then forced them to wear the Horn of Hades amulets to hide them from their mother, the Crone.

Vittoria describes how House Vengeance is isolated from the princes by a memory-wiping mountain range and then reveals that she was also cursed when she came to rescue Emilia. She declares her intention to reestablish House Vengeance and warns that Wrath’s curse prevents him from truly giving his heart. As Emilia prepares to leave, she warns Vittoria never to summon her against her will again.

Emilia’s soul slams back into her body. Wrath sits beside her, radiating controlled fury. Her skin is tinged blue from soul-travel. Wrath threatens to kill Vittoria if she ever takes Emilia against her will again, revealing that he’s the only thing protecting Vittoria from the other princes who want her dead. Emilia explains that Vittoria wants to reestablish House Vengeance, and Wrath says that he would never stop her from doing so.

They discuss Vesta’s disappearance. Emilia believes that Vesta is alive because Vittoria defensively avoids the topic. They theorize that Greed may have planted evidence to frame Vittoria and that Vesta, possibly a hybrid from outside the Seven Circles, might have used Pride’s portal to escape.

A red, pulsing anatomical heart pierced by a skull-hilted dagger appears in the sky. Wrath identifies it as the immortal heart, the symbol of the vampire court, signaling an emissary’s arrival. They go to his throne room, which Emilia has never seen. The gothic chamber features black marble, soaring ceilings, gold weapons, and a massive stained-glass window depicting the black wings stolen from Wrath. Emilia notices two matching thrones on the dais. Wrath tells her that she’s his equal and queen.

Servants bring arrangements of poisonous flowers, including Rosary Pea, which is lethal to vampires. Fauna, Emilia’s friend, delivers a necklace made of Rosary Pea berries and rubies, which Wrath fastens around Emilia’s neck as a warning. An older demon butler announces the emissary’s arrival. Anir, Fauna, and soldiers enter as Emilia and Wrath take their thrones. The vampire emissary, Blade, arrives with a female companion whose ancient, star-flecked eyes Emilia recognizes from nightmares. Wrath identifies her as Sursea, and Emilia realizes that she’s the First Witch.

Sursea needles Wrath about time passing and hints at a secret they share, enraging Emilia. She commands both visitors to bow to Wrath, summoning fire to compel their obedience. Her fury flares the chamber’s torches and singes Sursea’s leather gown before Emilia regains control.

Blade claims that he seeks an alliance, mentioning that Vittoria recently visited with Marcella, a demon-werewolf from the Shifting Isles. When Emilia asks if this was Vesta, Blade says no. Wrath exposes Blade’s deception, revealing that his forces eliminated multiple vampires found on House Wrath’s grounds. When Sursea draws a blade to threaten Emilia, Wrath freezes the witch solid in ice.

Anir brings in a chained vampire captured on the grounds. A charm is placed on her, transforming her appearance into an exact replica of Emilia, complete with identical tattoos. Under a truth spell, the prisoner confesses that she was sent to seduce and distract Wrath while Sursea kidnapped Emilia for the vampire court. Wrath kills the vampire by ripping her head from her shoulders. He hands the severed head to Blade, who reveals that she was the vampire prince’s betrothed. Wrath expels Blade with a threat of total war if the vampires attempt such treachery again.

Unable to sleep after the night’s events, Emilia goes to the kitchen. Wrath joins her and explains that royal vampires can enslave victims through their blood, which is why the vampire prince targeted her for her power. Over an herbed white-bean spread that Emilia makes, they theorize that Marcella might be Vesta and that her demon blood could prevent her from traveling to the Shadow Realm. Wrath notes that before the spell-lock, Emilia was never interested in cooking. They begin an intimate encounter in the kitchen, but Lust interrupts and summons Wrath to an arena called the Pit to watch a fight with their brothers.

Emilia goes to Celestia’s tower to research spell-locks. She finds grimoires filled with remedies and spells, including one for forgetting, but no direct solution for removing a spell-lock. Then, she discovers the recipe for a Bleeding Heart tincture, which is designed to prevent strong emotions like love from taking root. She realizes that Wrath has been drinking this pale purple liquor to suppress his feelings and avoid triggering his curse, which condemns him to lose everything he loves.

Emilia vows to end the curse by breaking her spell-lock and fully claiming Wrath, and Fauna agrees to help.

Emilia and Fauna test whether blood offerings can summon goddesses. They try small sacrifices to Fury and Death with no response, proving that gods cannot be summoned the way demons can. Emilia uses a summoning circle to call Domenico, who agrees to take her to Vittoria on the condition that Fauna remains behind. He drives his claws into Emilia’s shoulders to tether her and opens a portal.

They emerge at the monastery, not the Shadow Realm. Domenico explains that shifters can bypass gate restrictions, while demons are currently blocked from using portals to leave the Seven Circles. When questioned about the demon-werewolf Marcella, he grows defensive, insisting that no werewolf would bed a demon. When Emilia presses him about Greed, Domenico reacts violently, revealing that his father is dead but claiming that it was pack business.

Vittoria appears outside the monastery. Using her magic, Emilia tears away the glamour on the twins’ family home, revealing that it’s actually a temple. Vittoria then delivers the final blow: They’re not in Sicily. They’re standing on the Shifting Isles, the prison of damnation for mortal souls.

Emilia learns that the Shifting Isles shift between realities and timelines to maintain illusions for mortal souls sent there. She realizes that the witches never allowed them into the true mortal world. Vittoria explains that the isle contains infinite dimensions folded together, which is why it took Wrath so long to find them. Emilia deduces that Vittoria summoned Greed before her supposed death to alert Wrath to their location, and the twins reconcile briefly.

When pressed, Vittoria denies killing Vesta but refuses to reveal who actually died or where Vesta is. She insists that removing Emilia’s mortal heart is the only way to break the spell-lock. Emilia realizes that Wrath fears unleashing her full power, not her death, and decides to break the spell-lock anyway, choosing faith in herself over fear.

A young female werewolf brings a ritual gown. Emilia changes and lies on the altar. Vittoria drives her claws through Emilia’s chest and rips out her spell-locked heart. Agonizing pain overwhelms Emilia as her memories and power flood back. She loses consciousness.

When Emilia wakes at dawn, she has no heartbeat but possesses fully restored immortal senses and incredible strength. She tests her abilities by igniting flowers throughout the chamber with a word. Vittoria greets her as Fury, invites her to seize vengeance, and welcomes her sister back.