After three days of travel, the group enters the foothills. Grey suffers menstrual cramps, and Kier carries her pack despite her protests. Kier decides they need rest before the mountain crossing, so they stop at a remote inn.

Speaking to the innkeeper, Kier invents a cover story and rents two rooms. As he poses as Grey’s husband, his kisses stir Grey’s conflicted feelings. She reflects on her long-held, unspoken love for him and their habit of flirting without consequence. Over their first good meal in days, Sela suddenly begins to open up by defending Eron’s terrible cooking. Later, Kier plans a supply run to nearby Pista with Eron, disregarding Grey’s protests against his leaving the range of their tether. 

While Ola does laundry and Brit and Sela remain in the room, Grey goes downstairs and notices Luthrite men, realizing that they are hunters tracking the group. The innkeeper subtly warns Grey, who feels one man establish a magical tether with his well. Her military bearing and sword placement give her away, so she flees upstairs to warn the others.

Grey and Brit barricade the door and hide Sela under an overturned desk. Brit attempts to tether to Ola but cannot reach that far, so they try tethering to Grey instead. However, Grey is forced to reveal that she cannot tether to another mage like Brit because she and Kier are exclusively bound to one another.

The trackers force open the door, and four attackers enter. Grey kills one but is slashed across the arm. Brit, furious to be fighting without magic, takes severe wounds and is cornered. Sela suddenly pushes her power forward, revealing that she is a well, if only a weak one. Brit tethers to Sela and launches metal shavings through the room at lethal speed, killing the remaining three attackers.

Brit collapses, bleeding from multiple wounds. Grey sends Sela for her medical kit. When Sela returns, Grey sends her to fetch Ola, who is furious to see the carnage. Grey directs Ola to tether to Brit and performs emergency surgery, cleaning and stitching Brit’s worst wounds.

Eron returns first, then Kier, who reconnects their tether just as Grey mentally calls for him in panic. He takes command, helping Eron dispose of the bodies while deferring Ola’s angry questions. He brings Grey to another room to stitch her arm wound. Afterward, Grey breaks down and Kier holds her, apologizing for leaving. She falls asleep in his arms. Later, Grey awakens and insists on relieving Kier and Eron for watch duty.

A flashback reveals the origin of Grey and Kier’s bond. When Grey was 20, she and Kier endured a brutal eastern campaign, during which Kier’s captain constantly pushed him to use more of Grey’s power. In one battle, an Eprainish mage attacked Grey directly, attempting to drain her through an unwanted tether. Kier killed the man, but Grey was left traumatized by the violation. In the infirmary, a guilt-stricken Kier requested reassignment and asked for Grey’s medical dismissal, trying to protect her, but Grey refused to leave him and proposed the forbidden binding ritual to prevent anyone else from stealing her power. Kier knew that a binding would prevent him from using another well and would cause him to lose his magic if Grey were to die, but he agreed. They performed the ritual alone in their tent, using blood and true names.

In the present, Kier wakes Grey, saying they must leave. He plans to buy a horse for the injured Brit. Grey prepares a potion to cloud the innkeeper’s memory of the attack, which Kier administers. When Grey checks Brit’s wounds, Ola is openly hostile. Using her latent power as Locke, Grey nudges Ola’s tether and directs healing magic to fight Brit’s infection, shocking both of her companions.

The group gathers in the tavern. Ola confronts Kier and Grey, and Grey admits that she and Kier are bound. Sela’s ignorance of the binding ritual raises suspicion, and the others realize that the 15-year-old girl is too young to be Maryse, since Locke fell 16 years ago.

Kier demands to know Sela’s true identity. Sela reveals she is Wilisela Naudé. The name triggers Grey’s childhood memories of her parents discussing Cleoc Strata’s High Family. Kier identifies Sela as the First Daughter of Cleoc Strata, heir to an enemy nation.

Stunned by Sela’s revelation, the group quickly packs and flees the inn. They travel in tense silence toward the mountains, with Brit and Sela riding the horse Kier acquired. After some distance, Kier calls a halt. Sela explains that she was being educated in Lindan but became homesick, so she stowed away on a ship to Idistra. Discovered without papers and threatened with drowning, she lied and claimed to be Maryse of Locke. 

Now, Grey proposes continuing to Grislar as ordered, but instead of delivering Maryse, they will send word to Cleoc Strata and use Sela to broker a truce between that nation and Scaela. Sela agrees, confident that her mother will listen to her.

That evening at camp, Eron questions how magic can still exist if Locke is gone. Grey reflects privately that as the last living Locke, if she dies without an heir, all magic in Idistra will die permanently. Later, as she sits with Kier apart from the others, Grey admits that the screaming mountain wind reminds her of home. The narrative also reveals that years after they forged the letter, a teenage Kier suggested that she and Grey hide from the ongoing search for Severin by joining the army, lying about Grey’s age to enlist early.

Now, Kier gently suggests retiring to Lindan and leaving everything behind, though Grey notes that their magic likely would not work that far from Locke. Grey wonders aloud if she should stop running from her identity as Locke. Kier cautions against any hasty decisions.

Later, Sela asks Grey to explain binding. Grey describes it as finding someone who feels like home. When Sela bluntly asks if Grey loves Kier, Grey admits that she does. Sela then asks Grey to train her as a well, and Grey agrees to try.

The group endures four brutal days crossing the snowy Aloducan Mountains. Kier creates hand-sized magelights to prevent frostbite, drawing steadily from Grey. As they travel, Grey trains Sela to control her power and form stable tethers with Brit.

On the descent, Kier notes they are roughly five days from Grislar and plans to send letters from the next village to buy time. They make camp, and the group exchanges folktales about magic’s origins. Eron tells a story of gods blessing each nation with magic. Sela discusses how other nations view magic. Grey reluctantly shares a tale in which one Lindan explorer stole her lover’s heart out of fear of abandonment, making their magic dependent on their proximity to one another. The moral of her story is that magic requires both love and betrayal to function. Kier counters with a more romantic version in which the woman gave her heart freely as a promise to return. Grey knows that both versions came from her mother, who told different variants to her and Severin based on her mood. The exchange makes Grey think of Locke’s temple ruins, which were dedicated to the goddesses Retarik and Kitalma.

Later, they find an abandoned cottage for the night. Grey watches Kier with yearning, and her emotions leak through their tether. He catches her staring, and they discuss retiring to a place like this. After some banter and flirting, Grey pulls back emotionally. She is convinced that Kier’s constant flirting is not sincere and that he does not reciprocate her romantic love. Staring out at the mountains, she wonders if his platonic affection will ever be enough for her.

In an abandoned mountain house, Grey uses her power to ease Kier’s old knee injury, then reviews his draft truce proposal. Suddenly, Kier senses multiple heartbeats surrounding their position. On the roof, they confirm at least 30 enemies, including wells. Kier suggests that Grey escape with the others, but she refuses to leave him.

Kier orders the others to flee. Outside, Grey tells Kier that if they survive, she wants to resurrect Locke. They kiss—first lightly, then with desperate passion. Kier murmurs Locke’s motto.

Grey and Kier touch palms, and Grey reaches out and drains the surrounding 43 enemy wells, leaving their mages defenseless. She pushes the stolen power into Kier, who unleashes it on their attackers. The strain overwhelms Grey. She collapses, coughing blood, and sees fragmented memories of Severin and her mother’s death. She hears someone calling her name before she loses consciousness.