Kiernan Seward is a dynamic, round character who functions as the deuteragonist. A powerful mage with an affinity for the heart, he is publicly defined by his duties as a captain in the Scaelan army, but his greatest purpose in life is his self-imposed role as Grey Flynn’s devoted protector. His commitment to Grey’s safety is so absolute that it consistently overrides his institutional duties and personal ambitions. Whether Grey chooses to run from her past or turn and face it, he remains steadfastly by her side and supports her decisions, and his character arc explores the tension between fulfilling patriotic duties and remaining true to a loved one. Because he is determined to prioritize Grey’s safety no matter the cost to himself, his actions highlight the novel’s examination of Sacrifice as the Ultimate Expression of Love.

Despite his considerable power and rank, Kier is characterized by his compassion and empathy. Unlike many of his peers, who disregard “Hands” (wells) as somehow lesser than mages, Kier never views his well as a mere resource. Instead, he treats Grey as an equal partner, and this approach is depicted as a revolutionary act in the hierarchical military structure of their world. However, his instinctive tenderness for others sometimes proves to be a liability. For example, he gives his armor to the captured Sela because he sees her as a “just a girl…terrified” (33), and this impulsive act of kindness renders him vulnerable to her deadly knife attack, which leaves him gravely wounded. This incident highlights the fact that his humane instincts often clash with the brutal realities of war and the strategic necessity of remaining cautious. 

As these early incidents suggest, Kier’s most defining trait is his capacity for self-sacrifice. He is willing to give up everything for Grey, from his career to his life. When her identity is about to be revealed to the world, he does not hesitate to sacrifice his own identity by claiming her title and making himself a target to their captors, declaring, “It’s me… I’m Severin, Heir to the Well, Lord of Locke” (286). Because he knows full well that such a declaration is a death warrant, this act marks the culmination of Sacrifice as the Ultimate Expression of Love. However, only later does he realize that the forbidden binding ritual has indeed made him a Locke by bond: a transformation that gives him a legitimate claim to the Isle and complicates his and Grey’s future. As the two deal with the consequences of their binding, Kier’s journey forces him to reckon with the lasting consequences of his self-effacing devotion. In the end, he chooses a life bound to Grey and the Isle, willingly giving up his personal freedom.

Wilisela Naudé, initially known only as Sela, serves as a catalyst for the central plot. A dynamic character, she is the First Daughter of the nation-state of Cleoc Strata. Having been sent to the mainland, she grows homesick and takes it upon herself to stow away aboard a ship and return to her homeland. Upon being discovered, she gives in to fear and desperation and falsely claims the identity of the long-lost Maryse of Locke. Her lie is initially a tactic to escape execution, but she soon finds herself a captured pawn, and her presence in the narrative launches Kier and Grey’s mission to transport her to the High Lord Scaelas. 

During this journey, the shy, uncertain Sela acts as a foil to bold yet bitter Grey. Although both young women are of noble birth and have been separated from their homes and thrust into a conflict they do not fully understand, Grey resists the idea of returning to her roots, while Sela is in her current predicament because she was actively trying to return home. Although Sela is initially presented as an antagonistic figure, particularly when she stabs Kier with his own dagger, the quest structure of the narrative allows her to evolve into a stronger, more worldly young woman who gains a greater understanding of both the gritty realities and lofty politics of her world. In the end, her steadfast loyalty to Grey and the other members of the party prove to be a valuable asset that earns Grey the personal regard and military assistance of Sela’s mother, the shrewd, ruthless ruler of Cleoc Strata.

Ola Et-Kiltar (a well) and Brit Wyvern (a mage) represent a more conventional partnership. As Brit’s well, Ola is characterized by her sharp tongue, pragmatism, and fierce protectiveness, and her demeanor contrasts with that of Brit, a nonbinary mage who specializes in metalwork and uses their humor and levity to mask their battle-hardened resolve. Ola and Brit’s dynamic showcases a relationship built upon trust and mutual respect, even if it otherwise conforms to the standard military framework of the Scaelan army. 

When faced with Grey and Kier’s uniquely intense, forbidden bond, their initial role is to challenge the main characters’ habit of secrecy, and they point out that the pair’s refusal to share crucial information puts the entire party at risk. For example, when Grey is incapable of lending Brit any magic during a battle against dangerous pursuers, Ola erupts in a display of suspicion and anger, telling Grey, “Either you’re a heartless bitch who only thinks of your own mage…or you and [Kier] are bound” (163). Her blunt declaration forces a necessary confession that reshapes the group’s dynamics and allows them to begin building a slow-growing foundation of genuine but begrudging trust. As the journey continues, Brit and Ola prove to be steadfast allies, demonstrating their loyalty by guarding Sela and fighting alongside Grey and Kier. As they become trusted members of Grey’s inner circle, these two supporting characters become vital members of a found family that is forged by shared danger and sacrifice.

Eron Fastria is a typic (non-magical) officer who serves as a key supporting character within the group transporting Sela. He is a static, flat character who exudes an air of unwavering loyalty, quiet competence, and moral grounding. Though he initially questions the logic of their mission, his doubts are quickly superseded by his duty to his captain and his comrades. Eron represents the perspective of the common soldier caught in the machinations of ranking officers and sovereigns, and his pragmatic views ground the fantastical elements of the story in an everyday human context. His most significant action is his willingness to impersonate Hand Captain Flynn in a crucial moment, thereby protecting Grey’s identity from discovery by Commander Reggin. Because Eron undertakes this act of self-effacing loyalty without hesitation, the scene solidifies his role as a trustworthy and honorable ally. While he is not a central player in the magical or political conflicts that drive the plot, Eron’s steadfast presence provides the main characters with a measure of stability in the midst of the novel’s emotional and political turmoil.

Hand Master Mare Concord a her long-serving Hand to an upper-level mage, and she has long since become weathered and worn down by years of battle. Her presence in the novel serves as a stark warning to Grey about the potential fate of a well in the military system. Her cynical advice to Grey about mages—“They never need you as much as you need them” (11)—encapsulates the exploitative potential of the mage/Hand relationship. Mare’s self-effacing dynamic with her own mage, the rigid and ruthless Master Klare Attis, illustrates the traditional, hierarchical power structure that the protagonists’ forbidden bond actively defies. Mare’s eventual capture and death at the hands of the enemy confirms her belief that wells are ultimately disposable in the great game of war.

Grey’s older brother, Severin of Locke is a pivotal but posthumous character who exists only in flashbacks and in Grey’s traumatic memories and dreams. When the Isle of Locke is attacked, he makes a conscious decision to give his own life in order to save Grey. As the young Grey’s magic explodes around the two siblings, claiming Severin’s life and destroying the entire isle, this foundational event reshapes Grey’s entire life, forcing her into hiding and burdening her with survivor’s guilt. In Grey’s adult life, Severin often appears to her in dreams as a figure of fire, and this motif represents both the destructive trauma of the siblings’ past and the fierce love that motivated his sacrifice. In the aftermath of Locke’s destruction, Grey and Kier forged a letter to create the illusion that Severin, not Grey, was the surviving heir. This subterfuge serves to shield her from discovery for 16 years. During this time, the memory of Severin is a constant, haunting presence for Grey: a symbol of a choice that she can neither escape nor fully comprehend, as evidenced whenever she recalls his desperate plea, “Do you promise… to let us go?” (53).

A capable healer, Leonie is a minor supporting character who serves as a confidante for Grey. As a capable and pragmatic medic, she represents a sphere of life and connection for Grey beyond the intense, all-consuming bond that she shares with Kier. Grey’s brief romantic encounters with Leonie highlight Grey’s deep-seated loneliness and her longing for a form of intimacy that is not complicated by power dynamics and shared trauma. Leonie’s role is primarily to the protagonist with a grounded, trustworthy presence. She is one of the few characters who suspects the truth of Grey’s immense power as the heir of Locke long before this fact is revealed, and her choice to remain silent emphasizes her steadfast friendship and loyalty. Even when Grey has become burdened by the onerous duties of her true station, Leonie continues to offer Grey a rare source of stability and non-judgmental support. Leonie’s presence also facilitates the plot’s development when Kier overhears Grey relating a series of harsh truths that she has been reluctant to share with him.