Maddie spends a quiet morning in Fyngaard trying to write Chris a thank-you note for the story he lent her. Apollo reassures her, tells her to "just be" herself with Chris, and comforts her fears about the baby she may be carrying by insisting their future can finally be bright. After Apollo leaves to hunt, Maddie wanders the Winter Palace, notices guests are now fascinated by Lahn and Circe, and joins Circe, Finnie, Cora, and others in the library just in time to see Hans and Loretta reconcile with a kiss outside.

The mood breaks when a massive attack begins. Wolves flood the grounds and countless red, black, and blue missiles strike the palace's magical dome, dimming the sky. The library is sealed and guarded, but Maddie refuses to calm down until Chris and Élan are brought to her; when they arrive, the noise and violence outside frighten the children. Meeta then reveals her blocked sight has returned, and Maddie understands danger is about to break through, so she orders Meeta and Loretta to take Élan and Chris away toward the wolves just before the windows explode inward and black, red, and blue mist invades the room. Another Circe and Valentine appear, and Maddie, Circe, Finnie, and Cora are forced into a magical transport.

The four women land inside a huge magical cage in a stone chamber on Specter Isle, where Pol and the cruel version of Cora are waiting with Baldur. Helda, Edith, and Minerva soon appear, and the villains explain the purpose of the trap: they believe the women's pregnancies will produce extraordinarily powerful daughters because love across worlds and kingdoms has created unmatched magic, and they intend to steal those girls to control the wolves, the Northlands, the elves and dragons, and the Southlands. Pol taunts Maddie, claims the witches have foreseen her child, and reveals plans to kill Chris as well. When his possessive Cora challenges him, Pol beats her to death with his steel hand, showing the women exactly how disposable everyone is to him.

Circe then discovers that the women's shared bond can still create power in this place. By joining hands and thinking of the men they love, Maddie, Circe, Finnie, and Cora unleash a wave of multicolored magic that destroys the cage. Their escape stalls when the doors slam shut and Baldur and Pol attack again, but Franka arrives unexpectedly and confronts the witches. At the same moment, Apollo learns at the palace that the trap has been sprung; Valentine admits brute force alone cannot solve it and demands Franka be brought to her so Franka's vengeance can become a weapon. On Specter Isle Franka turns on Helda, Noc arrives disguised as Tor and shoots Edith, Derrik betrays Helda, and Lavinia rises alive, summoning magical allies who neutralize Minerva's monsters and imprison Minerva in ice.

Apollo reaches Maddie in time to cut Pol down before Pol can reach her again, and Lahn kills Baldur. Tor, Frey, and Apollo shatter Minerva's icy prison, and Minerva is executed. Valentine then returns everyone to the snow outside the palace, where Apollo has Helda awakened and delivers her to the waiting wolves as final justice. Once Maddie confirms that all the children and their allies are safe, she uses humor to defuse Apollo's rage, joking about dressing for the gale, and Apollo finally breaks into relieved laughter as he pulls her into his arms.