Darcy awakens; she and Darius have been locked into a room so that they do not go back to rescue Tory. From outside the door, Orion and Gabriel insist she rest. Darcy realizes that Lavinia’s curse (placed upon her during the Christmas Day battle, and which she previously thought had been lifted) is taking hold. The curse is draining her magic and making her feel frighteningly mortal. Orion and Gabriel are distressed to learn about Darcy’s curse and the former vows to find a cure. When Tory returns safely, Darcy reveals to her that she is cursed.

Darcy and Orion travels to the secret Library of the Lost, where they are met by Gabriel’s friend, Laini. She guides them through a magical underwater entrance to a vast, cavernous library. They conscript some of Laini’s friends, to research the missing gemstones while they focus on reading about dark magic in hopes of finding a way to lift the curse. Eventually, they find a book which reveals that Phoenixes can combine their flames to break curses. Happy and relieved to have solved the problem, they explore the library together.

Back at the Burrows, Tory and Darcy have been working together to use their close bond and combined magic to gradually eliminate the curse from Darcy’s system. It is too soon to tell if it is working but they remain hopeful. One day, Darius confesses his fear to Tory that he will die in the war against his father before they can have a future, even suggesting they marry. They are interrupted by screams from the tunnels. They discover a woman’s mauled corpse and briefly see a large, hairy beast fleeing the scene. They alert the others, and Hamish places The Burrows on lockdown while a search is organized.

Just as Tory and Darcy are about to join the search party, Gabriel arrives. He tells them that a vision has revealed that it is time for them to visit the Palace of Flames to learn the ways of their ancestors. He transports them to a remote jungle and explains they may be gone for months or even a year. He leaves them before a set of huge golden gates. As the twins step through, the palace’s ancient magic forces them into their Phoenix forms and the gates slam shut behind them. A magical female voice welcomes them.

As Darcy and Tory enter the Palace of Flames, the ancient, overgrown ruins magically come to life. In the throne room, they encounter the ghost of their powerful ancestor, Queen Avalon Vega. Avalon confirms she is the one who banished Lavinia to the Shadow Realm centuries ago. She explains that a prophecy foretold their arrival and that she will train them in the ways of ancient Phoenix magic.

Avalon warns the twins that they will inevitably fight each other for the throne, a claim they vehemently deny. When they ask what happened to the Phoenix Order (the twins are the only known members of the Order), she claims not to know. Avalon begins their first lesson: creating a living Phoenix bird from pure fire. Darcy feels Lavinia’s curse weakening in the palace’s powerful atmosphere.

Back at the Burrows, Orion and Darius hunt for the murderer. They find Justin Masters (Geraldine’s fiancé) trying to wash blood from his clothes and arrest him, even though Justin insists that he is innocent. They then learn from Geraldine that the twins have left for the Palace of Flames and could be gone for months, which enrages Darius. A Fae named Leon, who is friends with Gabriel, tells Darius and Orion that he knows the location of one of the missing gemstones. Darius refuses to go, still furious about Tory’s absence. Orion, Caleb, and Seth set off with Leon, who takes them to his hometown of Alestria.

The mission is successful and they return to the Burrows with a golden-brown topaz gem (they now have seven out of twelve). Darius, still distraught, joins Orion in his room. They use Diego’s magic hat to access magical visions and Diego’s father, Miguel Polaris, appears to them in a vision. Miguel explains that his wife, Drusilla, was loyal to Lavinia and used dark magic to control and manipulate him. Miguel explains that not all Nymphs are loyal to Lavinia and some would like to see her defeated. Miguel explains that to defeat Lavinia, they need to locate and close all of the “rifts” (portals). He also reveals that Vard’s magical eye can help them to locate the remaining rifts.

At his palace, Lionel Acrux is pleased that the rebels closed a shadow rift, as it has weakened Lavinia and made her more submissive. He reflects on his ruthless rise to power, which included murdering his brother, Radcliff. Stella Orion arrives to beg for mercy for her son, Lance Orion: she wants Lionel to promise that he won’t kill Orion if the latter is captured as a rebel. Lionel refuses but becomes distracted when Lavinia summons him to show him a newspaper article. The article reveals that Catalina (Lionel’s former wife and the mother of Xavier and Darius) is alive (Lionel was previously tricked into believing she was dead). She has publicly divorced him, married Hamish Grus, and exposed Lionel’s history of abuse, coercion, and sexual exploitation.

Furious, Lionel searches for his butler, Jenkins, only to find Lavinia eating the man’s dismembered corpse. Lavinia then overpowers Lionel demanding that he marry her immediately. She forces him to speak the necessary vows to legally and magically bind them together. Under the sway of Lavinia’s magic and power, they have rough and violent sex. Immediately after, her stomach swells due to a magical pregnancy and a monstrous, long-limbed shadow creature claws its way out of her body and greets a horrified Lionel as “Daddy.”

Max senses the negative emotions of the rebels living in the confined space of The Burrows. Caleb (who has periodic contact with his mother) finds Max and reports that Lionel keeps the Councillors busy with menial tasks and has publicly celebrated his marriage to Lavinia. The younger siblings of the Heirs continue to be treated as the new Heirs. Caleb also confesses his intense connection to Seth, which has become a possessive and worrying obsession.

Their conversation is cut short when Gabriel gathers the group and reveals a new plan to acquire Vard’s magical eye. He instructs the rebels to imagine countless fake assassination plots: these fake plots will distract and confuse Vard when his psychic powers register them. While Vard is distracted, they will steal his eye. Orion, Darius, and Geraldine are assigned to infiltrate the palace; the team must only injure Vard, not kill him. Meanwhile, the rest of the group—Gabriel, Max, Caleb, Seth, Xavier, and Leon—will create a diversion by attacking Lionel’s newest and most heavily fortified Nebular Inquisition Centre (detention camps set up to imprison, torture, and persecute specific Fae Orders).

Darius, Orion, and Geraldine infiltrate the tunnels beneath the Palace of Souls. Darius grows increasingly frustrated with Geraldine’s bizarre and indirect route, though he and Orion both sense they are being followed. Deeply distressed about being separated from Tory, Darius confides in Orion his fear that he will die before she returns. He makes Orion swear to look after Tory if he dies.

They encounter a magical vision from the spirit of Queen Merissa. They witness an alternate reality where Lionel never seized power. In this timeline, the Vega twins were raised at the palace alongside the Heirs, and they all grew up together, falling in love and preparing to rule a peaceful Solaria. The vision of this stolen future leaves Darius grieving, the anguish compounded by the knowledge that he is only months away from his own fated death.

At the Nebular Inquisition Centre, Seth uses magic to distract Lionel, Lavinia, and the Nymphs, creating fake crowds of escaping rebels to draw their fire. While the real prisoners flee, Seth shifts into his Wolf form to rescue two small children from a Nymph. He then learns that Caleb is in trouble.

Seth finds Caleb overwhelmed by three Nymphs and leaps into the fight, killing the attackers just as Caleb is knocked unconscious. Enraged, Lionel attacks them with Dragon fire. Seth and Caleb combine their magic to tunnel underground to escape. Believing they might die, Seth tells Caleb he loves him. Caleb responds that Seth is his “ride or die,” which Seth interprets as a sign that Caleb only cares for him as a friend and does not harbor romantic feelings. Seth resigns himself to unrequited love for Caleb.

Orion, Darius and Geraldine finally reach Vard’s chambers, where Geraldine swiftly immobilizes the sleeping Seer and surgically removes his magical eye. Darius and Orion leave Vard maimed but alive. As they escape, Geraldine is ambushed and trapped by a monstrous, spider-like creature but Orion and Darius fight and kill the beast. They successfully escape the palace with the eye.

Caleb and Seth continue distracting Lionel and Lavinia with illusions. When the illusion flickers for a second, Lionel and Lavinia realize they are being tricked. They immediately flee to return to the palace; Lavinia is desperate to protect their heir (the monstrous creature she birthed).

After neutralizing a group of Fae working for Lionel and encouraging them to join the rebellion, Caleb and Seth return to The Burrows. Caleb kisses Seth, who responds by performing oral sex. Afterward, Caleb wants to reciprocate but is nervous about his lack of experience. When he tries to express his hesitation, Seth misreads this statement as rejection, panics, and denies any feelings before fleeing the room. Caleb is left alone, hurt and confused.

Seth is devastated, convinced that Caleb rejected him. He wanders the tunnels in misery, convinced he has permanently destroyed their friendship. Orion finds him whimpering in a dark corner.

Seth confesses to Orion about the oral sex with Caleb and fled after being rejected. Orion advises him to be honest with Caleb and talk through what happened. Ignoring this, Seth decides his best course of action is to bury his feelings and pretend the encounter never happened, hoping the problem will resolve itself.

Four months pass. Tory and Darcy have become formidable warriors under Queen Avalon’s training at the Palace of Flames, but they are restless and eager to return to the war. Darcy’s curse has significantly faded. For their final test, Avalon presents a crown and demands that one of them defeat the other to claim it, insisting only one can ascend the throne.

The twins refuse to fight each other. Instead, they combine their power to summon a massive, unified Phoenix. The creature attacks Queen Avalon, destroying her ghostly form and the throne in a fiery explosion. The crown survives but is split perfectly in two. With the test passed, the palace gates open. The twins return to The Burrows, where they are ecstatically greeted by their friends and allies. Darius and Tory enjoy a passionate reunion. Tory also learns that Justin Masters remains in prison; his guilt has not yet been confirmed, but everyone is convinced that he is the killer.

Gabriel teases Orion about his growing friendships with the other Heirs. Orion confides in Gabriel about his relationship with Darcy, explaining that he feels he must hide their love to protect her from the social fallout of his Power Shaming. Gabriel glimpses a vision that this secrecy could backfire and cause the rebels to turn against Darcy but keeps it to himself. Later, Xavier plays a prank on Gabriel (he previously promised to do so in exchange for his piercings). Gabriel is left furious with Xavier.