After a brief meeting of the commanders, Kier gives Grey a formal farewell. The injured Eron stays behind with Grey while Ola and Brit join the field. Cleoc leaves, taking with Eron with her so that he will not be able to restrain Grey if she should decide to join the battle after all. Grey dons the armor that Sela gifted her, takes her sword, and climbs to the tower. Watching the fighting rage on Osar’s beaches and in the harbor, she decides she cannot remain behind.

She slips from the fortress, kills a Luthrite mage in the Ghostwood, and follows Kier’s path, finding him fighting alongside Ola and Brit. He welcomes her presence, and the Isle’s power flows through her as they fight together. Kier admits they are losing ground and orders a retreat toward the Ghostwood.

A Luthrite soldier attacks Grey, who pulls away his power on reflex, revealing who she is. He shouts out that she is Locke, then lunges at her. His sword pierces her side before another blade cuts him down. Kier catches Grey as she collapses. Through her connection to the Isle’s power, Grey feels every death, including a flare of agony from Ola. She apologizes to Kier before losing consciousness.

Grey wakes in a metaphysical space where the battlefield appears empty except for threads of colored light, the brightest gold representing Kier. Her wound bleeds golden light. The ghost of her mother, Alma, appears and explains that Grey is witnessing her full inheritance; as Locke, she is the root of all power in Idistra and can bestow or revoke magical power from entire nations at will.

Alma leads Grey to the altar in the Ghostwood cemetery and teaches her to sense the power threads. Grey identifies the tethers belonging to her enemies and snaps them all, pulling their power into herself. Alma then presents Grey with a choice: die and join her parents in the afterlife, or return to her body with no guarantee of survival. Unwilling to abandon Kier or make another decision without him, Grey chooses to return. Alma lays Grey on the altar and tells her to wake up.

Grey wakes on the battlefield, where Kier confirms that the enemy has lost their power and is retreating. As he carries her to the fortress, she passes out again. Later, she wakes in her bed with Leonie watching over her. Leonie confirms that Grey stripped Eprain and Luthar of their magical power. Grey decides to use this as leverage for peace. Leonie reports 2,000 allied dead and 4,500 enemy dead. Scaelas is injured but will recover, and Ola will lose her arm. Commander Reggin is one of the casualties. Kier arrives, and they banter before he insists that Grey rest.

After two days, Grey sneaks to her office at night, where Scaelas joins her. Grey asks for his advice on how to handle her enemies, and he says that she has proven her point and should pursue peace. They wake Cleoc, and by dawn they have a treaty. Within a week, peace agreements are reached with all six nations. Two weeks later, Grey restores power to Eprain and Luthar.

The Isle begins to repopulate with defenders and their families. Grey establishes a routine of sparring with Ola, holding receptions, and governing alongside Kier. Her days are filled with meetings and correspondence, including letters from Kier’s mother and Grey’s friend Imarta, who plans to visit for an upcoming feast. Cleoc visits to say goodbye. Leonie, Brit, Ola, and Eron all declare their intention to stay on Locke. After a farewell dinner, Scaelas tells Grey that her parents would be proud.

That night, Grey meets Master Attis at a pub and tells her how Mare died. Still restless, she goes to the tower and sees Kier’s magelight on a secluded cliff ledge overlooking Scaela. She joins him and finds him crying over the loss of his freedom. He affirms that he will not run and will bear being bound to her and the Isle. Through their tether, she communicates her love and gratitude, which he reciprocates.

On the night of the full moon, Grey and Kier stand before the altar in Kitalma’s ruined temple. Grey offers Kier one final chance to reconsider, but he refuses. When the goddess appears, Grey declares that she will keep her power. Kier states that he will surrender his freedom. Kitalma places her hand on Kier’s chest, and something golden and formless passes from him into the goddess. For a moment, Grey glimpses a second armored figure—Kitalma’s lover Retarik. Kitalma pronounces Grey and Kier bound to the Isle and to each other, then wishes that their union will be long and sweet. She fades away.

Kier jokes that the ritual felt like a marriage ceremony. He admits to feeling sad but reassures Grey that he is all right. As they walk back toward the fortress, he tells Grey that she is stuck with him forever. She replies that she can tolerate him forever.

Three months after Locke’s restoration, the Isle thrives during a week-long festival. In Grey’s rooms, Kier plays cards with his mothers, Pia and Laurella, and her friend Imarta while Tress, Grey’s attendant, announces arrivals. Sela, Ola, Brit, and Eron join them. Brit hints at a secret that they share with Grey, making Kier curious.

After the others leave for the feast, Grey brings Kier down the cliffside path to a secluded ledge, where she reveals a newly built cottage replicating his childhood home. The master bedroom has a window overlooking Scaela. Overcome with emotion, Kier cries.

Grey tells him that the cottage is his alone; she cannot give him his freedom but wants to grant him a private space. He asks her to stay the night and to skip the party, then tentatively asks if he, too, can share the title of Locke. She asks if he wishes it. He replies that he does. She agrees, calling him Locke.