A resilient young woman from New York City who withdrew to an upstate cabin following a traumatic incident, only to be kidnapped. She has spent the past five years imprisoned by Aidan, who forces her to abide by rigid rules and conceals her identity by presenting her as a renter. A former runner, she utilizes hypervigilance and a deeply analytical mind to survive her daily trauma.

A widower and veteran who is a valued member of his small upstate New York community. Outwardly, he projects the image of a ruggedly handsome and politely reserved family man. In reality, he harbors deeply sadistic impulses and maintains a double life, meticulously compartmentalizing his violent crimes from his respectable public persona.

Aidan's thirteen-year-old daughter. Reeling from the recent loss of her mother, she feels intensely isolated and struggles to comprehend her father's rigid exterior and apparent lack of mourning. She is an intelligent girl who loves trivia and begins displaying typical adolescent rebelliousness as she adjusts to her complicated home life.

A woman in her late twenties who owns and operates a local restaurant she inherited after her parents' sudden deaths. Despite a supportive staff, she struggles with profound loneliness and craves intimate connection. She develops an intense, obsessive romantic fixation on Aidan, finding increasingly bold ways to insert herself into his daily routine.

Aidan's late wife and Cecelia's mother. She died following a five-year battle with cancer prior to the main events of the story. During her life, she believed Aidan to be a devoted husband, defending him against her parents' clear mistrust.

The chef at Amandine. He is a steadfast part of the supportive, tight-knit restaurant staff that surrounds Emily in her daily operations.

A local judge who owns the rental house that Aidan and Cecelia move into. He utilizes his community standing to organize a charity race benefiting the grieving family.

A friend from May's past in New York City. She created a custom silver infinity pendant with rose quartz for her friend, an item that later becomes a significant clue.

A sex worker who interacted with Aidan during his college years. Her final hours establish the early pattern of his violent and impulsive crimes.

A shop worker targeted by Aidan shortly after his engagement. She observes his chilling dispassion and self-control while he secures her.

A victim targeted right before Cecelia's birth. She listens to her captor express mixed emotions about his ability to be a good parent.

A resourceful woman who nearly escapes by utilizing her knowledge of the local woods. Her near-escape deeply unsettles her captor.

A captive who hears Aidan admit that he has been making errors in his recent attacks, illustrating the gradual deterioration of his meticulous control.

A fiercely resilient woman whose sudden disappearance alarms the local community. She fights back violently, shocking her attacker with her absolute refusal to surrender.

A wounded animal that appears outside the house one night. Despite Aidan's desire to euthanize it, the dog survives and becomes a source of comfort for the household.