Avery is an intelligent, ambitious high school junior who has grown up in poverty. She works as a waitress and lives with her half-sister, Libby, before unexpectedly inheriting a multibillion-dollar fortune from a man she does not know. Resilient and analytical, she has a talent for math and a deep appreciation for games and puzzles, traits she must rely on to survive her dangerous new life at Hawthorne House.

Tobias is a deceased Texas billionaire and philanthropist who built a massive fortune and an elaborate, puzzle-filled mansion. Known for his manipulative nature and love of complex games, he disinherits his entire family in favor of a teenage stranger. Even after death, his presence looms large as he dictates the actions of his heirs through a series of difficult clues.

Grayson is the nineteen-year-old heir apparent to the Hawthorne fortune. Impeccably dressed in Armani suits, he is deeply devoted to his family and highly suspicious of Avery, believing her to be a manipulative gold digger. He approaches life with a serious, calculated demeanor and harbors lingering guilt over a past tragedy.

Jameson is the second-youngest Hawthorne grandson, characterized by his thrill-seeking nature and desperate hunger for a challenge. Devastated by grief and past trauma, he immediately views Avery not as an enemy, but as his grandfather's final, brilliant puzzle to be solved.

Known to Avery early on as Harry, a homeless man she frequently plays chess with and buys breakfast for. Within the Hawthorne family history, Toby is Tobias's beloved son and the boys' uncle, whose tragic disappearance in a fire years prior profoundly altered the family dynamics.

Libby is Avery's optimistic, blue-haired older half-sister who works as an orderly. She is fiercely protective of Avery and serves as her primary emotional support system when they move to Hawthorne House. Despite her kind heart, she struggles with a toxic relationship with her ex-boyfriend, Drake.

The eldest Hawthorne grandson is a slow-talking, motorcycle-riding cowboy who distances himself from the family's competitive games. He views the inheritance drama with detached amusement and frequently tries to rescue people in distress, showing a protective interest in Avery's sister, Libby.

The youngest Hawthorne grandson is a charismatic, fast-talking teenager who describes himself as a multiracial James Dean. He has an affinity for building complex Rube Goldberg machines and often acts as a friendly, laid-back guide for Avery as she explores the bizarre mansion.

Skye is Tobias Hawthorne's daughter and the mother of the four Hawthorne grandsons. She presents herself as flighty, laid-back, and eccentric, often focusing on superficial details while remaining fiercely invested in her sons' standings within the estate.

Zara is Tobias's strict, bitter daughter who runs the Hawthorne Foundation, and Constantine is her husband. The couple operates as a united, hostile front, leading the legal and public relations battle to challenge Avery's inheritance and regain control of the family's wealth.

Thea is Constantine Calligaris's niece and a student at Heights Country Day School. Cunning and musically voiced, she hides her identity initially and seems intent on manipulating Avery, using her knowledge of the Hawthorne family's dark past to keep Avery off balance.

Drake is Libby's abusive, opportunistic ex-boyfriend. When news of Avery's sudden billionaire status breaks, he immediately leaks information to the press and attempts to exploit Libby's proximity to the fortune, serving as a volatile external threat to the sisters.

Emily is the deceased granddaughter of the estate's caretakers. Described as wild and adventurous despite a severe heart condition, her untimely death created a deep, lingering rift between the Hawthorne brothers, haunting the mansion like a ghost.

Rebecca is Emily's quiet, responsible surviving sister. She is deeply steeped in grief over her sister's death and behaves cryptically around Avery, torn between her loyalty to her family's secrets and the unfolding events at Hawthorne House.

Avery's late mother was a single parent who struggled financially but possessed a brilliant, playful mind. She frequently invented games to distract Avery from their poverty, though her penchant for keeping secrets ultimately had devastating consequences before her death.

Alisa is a composed, professional attorney from the firm managing Tobias Hawthorne's estate. Tasked with handling Avery's transition into high society, she coordinates everything from legal defense to media training, all while managing her own awkward history with the Hawthorne family.

Oren is the highly capable, protective head of security at Hawthorne House. Fiercely loyal to Tobias Hawthorne's last wishes, he becomes Avery's constant shadow, shielding her from media frenzies, angry relatives, and physical threats as she investigates the estate.

Max is Avery's fiercely loyal, long-distance best friend. Because of her strict parents, she communicates using elaborate, coded curses. She serves as Avery's vital tether to her normal life, frequently offering blunt advice from afar regarding the dangerous Hawthorne world.

The Laughlins are the elderly couple who manage the cooking and domestic duties at the estate. They are deeply protective of their granddaughters and exhibit a distinct, quiet coldness toward Avery following her arrival at the mansion.

Mellie is a young staff member at Hawthorne House who was given her job through Nash's charitable interventions. She appears protective of her connection to Nash and views Avery and Libby's sudden arrival with evident suspicion and displeasure.

Nan is Tobias Hawthorne's elderly mother-in-law who resides at the estate. Though largely relegated to the background, she carries the scars of a dark and abusive past and holds quiet knowledge about the family's oldest tragedies.

Ricky is Avery and Libby's absent father. His primary relevance to the sisters is the threat of his sudden reappearance, as Avery's newfound wealth presents an opportunity for opportunists from her past.