Norbridge Falls is a mentor and guardian archetype for Elizabeth, and his eccentric, kind, and mysterious nature makes him the heart of Winterhouse. As the proprietor of the hotel, he is the steward of his family’s legacy, a responsibility he balances with a playful, magical flair. His introductions are often accompanied by coin tricks and a theatrical charm, which initially presents him as a whimsical figure. Beneath this playful exterior, however, lies a concern for the hotel’s safety and a sadness at the loss of his daughter, Winnie. His concealment of the dark history surrounding his twin sister, Gracella, enables the mystery plot. Thus, he is a round character, possessing both a lighthearted public persona and a private, worried side that is revealed as the central conflict escalates.

Norbridge’s primary motivation is the protection of Winterhouse and its unique, positive spirit. His secret, late-night searches in the library for “The Book” are driven by an inherited duty to solve his grandfather’s puzzle and safeguard the hotel from the potential evil it could unleash. His request for her to check in with him twice daily is a manifestation of this protective instinct, which is later revealed to be an intuition about her true identity as his granddaughter. This relationship is central to Elizabeth’s arc, as he provides her with the safety and acceptance she has never known, allowing her to flourish. As a powerful magician himself, Norbridge understands the responsibilities that come with supernatural ability. He is a moral guide for Elizabeth, especially after she discovers her own powers, warning her that power “is not to be taken lightly” and that pride in one’s abilities can lead one astray (368). This wisdom comes from his experience with Gracella, whose turn to dark magic is a cautionary tale. Norbridge embodies the benevolent use of magic, employing it for wonder and protection, contrasting with Gracella’s quest for power and destruction, illustrating the theme of Magical Power as an Expression of Moral Character.

Freddy Knox is the book’s deuteragonist, a highly intelligent and logical boy who becomes Elizabeth’s first true friend. Freddy begins as a somewhat isolated figure, sent to Winterhouse by wealthy parents who he feels neglect him, but he finds solace and purpose in intellectual pursuits, particularly anagrams and his invention, the “Walnut WonderLog.” His immediate connection with Elizabeth over wordplay establishes a friendship built on mutual respect for each other’s intellect. This bond is important for Elizabeth, as it provides her with a peer who understands and values her in a way no one else has, contributing to the theme of Finding Belonging After Loss.

Freddy’s character reinforces the idea of finding a place where one’s unique talents are appreciated. At Winterhouse, Norbridge gives him a workshop and encourages his inventive spirit, a stark contrast to the lack of interest he perceives from his own parents. His successful creation of the Walnut WonderLog is a personal triumph that proves his abilities have real-world value. His friendship with Elizabeth is similarly affirming, as they engage in friendly competition with word ladders and collaborate on scavenger hunts, turning their shared love of puzzles into a source of joy and camaraderie.

The partnership between Freddy and Elizabeth is presented as the ideal team: enough shared interests to be tight-knit but with complementary skills that they each increasingly learn to value in the other. As such, Freddy often acts as a foil to Elizabeth. Where she is impulsive and driven by intuition, Freddy is cautious and relies on logic. He is frequently the voice of reason, questioning the wisdom of her plans. This is presented as a pragmatic assessment of risk, although his loyalty to Elizabeth increasingly pushes him to overcome his fear. Despite his initial reluctance to get involved in the hotel’s darker secrets, he stands by Elizabeth, even joining her in the frightening final confrontation in the library, demonstrating his growth from a solitary inventor to a brave and steadfast friend.

Gracella Winters is the primary antagonist of the novel, a malevolent spirit whose history and motivations drive the central conflict. As Norbridge’s twin sister, she fits the “dark twin” archetype of supernatural fiction, representing the dark potential of the Falls family’s magic. Characterized by jealousy and a lust for power, Gracella turned to dark arts after being slighted by her father, who chose Norbridge to inherit Winterhouse. Her threat to one day destroy the hotel, which she made as a child, festers into a lifelong adult preoccupation, making her the novel’s cautionary figure in its middle grade message of emotional development and personal responsibility. Even after her physical death, her body is unnaturally preserved and her spirit—symbolized by the pursuing crimson light—remains unquiet, demonstrating her character’s willful inability to find reconciliation and peace.

As Gracella’s role depends on her refusal to learn and change, she is a static and flat character, motivated by a desire for destruction and control. Her actions are entirely “evil,” with no moments of sympathy or complexity. She exploits her daughter, Selena, and son-in-law Marcus as pawns to facilitate her return and to locate The Book, which she believes will grant her ultimate power. When she is resurrected, Gracella’s first actions are to incapacitate Norbridge and threaten Elizabeth and Freddy. As the embodiment of the wrong moral choices, Gracella is defeated when Elizabeth makes her own—opposite—moral choice, making her central to the theme Magical Power as an Expression of Moral Character.

Marcus and Selena Hiems are the novel’s apparent antagonists for most of the story, acting as agents for the disembodied spirit of Gracella Winters. As the most likely antagonists, their role in the narrative is to create immediate tension and mystery, complicating the reader’s understanding and expectations of the “evil” force referred to in Winterhouse’s legend. The couple’s sinister nature is established early on through their menacing behavior on the bus and their insistence on privacy at the hotel. They are a constant, physical threat within the hotel walls, and their strange actions, such as examining the bridge and attempting to enter the library at night, arouse Elizabeth’s suspicion, triggering her investigation. Marcus’s business card, with a signature that reads “Sweth” upside down, provides an important link to Riley Sweth Granger, the author of The Book, deepening the puzzle for Elizabeth. 

When Selena is revealed to be Gracella’s daughter, tasked with preserving her mother’s body in a crate and engineering her return to power, the Heimses’ true purpose is revealed. As static, flat characters, they are defined entirely by their goal to see Gracella restored to power: After Gracella’s defeat, they vanish from the hotel, signaling their continued allegiance to her and creating a potentially complicating loose end for the Winterhouse sequel.

Leona Springer, the librarian of Winterhouse, is a kind and knowledgeable mentor figure for Elizabeth. As Norbridge’s oldest friend, she is privy to the secrets of the Falls family and the legend of The Book. The library is her domain, and she presides over it with a deep love for literature and a gentle authority. She is the first adult at the hotel, besides Norbridge, to recognize and appreciate Elizabeth’s intelligence and passion for reading, creating a welcoming and safe space for her. Leona is often a no-nonsense foil to the magical Norbridge, such as when she calls Norbridge out: “There's a difference between ‘knowing’ something and just having a funny feeling” (350), balancing the novel’s supernatural elements with a down-to-earth commitment to learning and hard work.

Leona’s bond with Elizabeth over books reinforces the idea that shared passions can forge strong, family-like connections, contributing to the theme of Finding Belonging After Loss. She acts as a source of important exposition, providing Elizabeth with Marshall Falls’s journal and sharing the history of Gracella’s turn to dark magic. Her loyalty to Norbridge and her protective feelings toward Elizabeth make her a steadfast ally in the face of the hotel’s looming threat.

Aunt Purdy and Uncle Burlap are Elizabeth’s neglectful guardians and establish the bleak circumstances from which she escapes. They are minor characters only shown through the unpleasant note they leave duct-taped to the door and Elizabeth’s remembered experiences, defined by their selfishness, miserliness, and emotional coldness. Their shabby house and dreary routines provide a deliberately unhappy baseline for Elizabeth’s life, contrasting with the vivid, magical atmosphere of Winterhouse. Their irresponsible willingness to send Elizabeth away for their own financial gain, accepting $5,000 to fund their own vacation, facilitates the novel’s premise: Their role is to provide this device and to provide a foil to Elizabeth’s sense of belonging at the hotel.