Aboard his ship, King Theodore studies a book on dark magic titled A New Age of Terrible Magic, trying to understand the physical toll spells take, as he is haunted by the memory of Imogen’s suffering. His chancellor, Eftan, confronts him, furious that Theodore has amended his marriage contracts to remove the traditional blood binding with Princess Halla. Theodore claims the changes are for Varya’s safety, but Eftan accuses him of altering them to leave open a future with Imogen. 

To demonstrate the extreme measures he will take to protect the crown, Eftan confesses to murdering Theodore’s father’s mistress to remove her as a distraction, then manipulating the king into transferring the crown to Theodore—a sequence Theodore recognizes as having caused his own premature ascension. He then produces the binding gown Theodore gave Imogen, claiming it was found discarded aboard the Hercule as proof of her rejection. After Eftan leaves, Theodore discovers a strand of Imogen’s hair on a button, proving she wore the gown before she left. Feeling powerless and trapped by his duty, he stores the dress and prepares for the wedding.

Hiding in a palace armory, Imogen tells Lachlan that she made a bargain with Eusia and that they must kidnap Halla to force the princess—who can perform magic—to help sever the bond. Seeing this as his only chance to rescue Agatha, Lachlan agrees. Imogen creates a diversion by setting fire to the cloth draped over the statue of the Great Goddess Diantan in the main hall, allowing them to escape the palace grounds undetected in a hay wagon. Under the influence of nepenthe, a pain-dulling draught, she experiences a vision of a young Nemea enacting a spell by Eusia, forging bonds to access her power. Imogen awakens as they arrive at the port, only for Lachlan to inform her they are too late—Theodore’s ship has already sailed.

At the docks, Imogen initially refuses to use her power to pursue the ship, fearing she might lose control due to Eusia’s influence and harm Theodore. Lachlan angrily reminds her of her duties, pointing out that as the self-proclaimed Queen of Seraf, her actions now have political consequences. Convinced, Imogen writes a letter to Seraf’s royal council, announcing she has killed Nemea and is claiming his throne by right. Lachlan’s sister, a ship captain who agreed to help because she liked Agatha, delivers the letter and provides them with a dinghy. Imogen summons a sea current to propel them toward Theodore’s warship, the Eleuthios, but the effort severely drains her strength. Too weak to climb aboard, she summons three undead Sirens known as nekgya from the water. The monstrous creatures silently scale the ship and lower a rope ladder, leaving Lachlan horrified by this display of her new, dark power.

On the deck of the Eleuthios, Imogen collapses as her magical stomach wound begins bleeding. A patch of kelp is fused to her charred skin. Lachlan insists on getting the ship’s healer. While he is gone, the ship’s musicians begin playing the song she and Theodore first danced to, leaving her devastated. A sailor discovers them, and when he aggressively grabs Imogen, she gravely wounds him with her taloned hand; Lachlan pushes the still-gasping man overboard. 

The ship’s healer, Carras, arrives and identifies the injury as a spell-wound that cannot be removed, only treated for infection. Carras suggests Theodore’s healing could work, but Imogen refuses to see him. After giving her nepenthe for the pain, Carras orders her to bedrest and places a blue band on her arm to signify her medical status. Lachlan creates aliases for them: Third Officer Lachlan and Mariner Cadet Imogen. As he settles the heavily drugged Imogen into a hammock, he tells her the ship’s course will pass Anthemoessa. She begs him to wake her before the midnight wedding, but he gives a noncommittal response.

On the main deck, Theodore feels trapped as he watches the final preparations for his wedding. His steward, Markis Gabros, offers cynical advice, suggesting that love is fleeting and that avoiding a true marriage bond is a wise decision. Theodore refutes this, recounting a story of his grandfather, the Great God Panos, who remained “possessed” by his love for his wife long after her death. 

The ceremony begins, and Halla speaks her vows and cuts her palm in a blood rite that Theodore’s anger makes clear she was not meant to perform. At that moment, the wind and sea fall unnaturally still, making Theodore think of Imogen. The moment passes, and he resignedly places the bloodied ring on his finger but refuses to cut his own palm. He speaks vows committing himself only to her “crown” and their political “agreement.” Halla kisses him, finalizing their marriage as an incomplete union without a true blood bond.