Linda, born Madeline Furston, is an emotionally distant 15-year-old growing up in complete isolation in an abandoned hippie commune with her parents. She struggles to connect with her peers and prefers the company of dogs and the wilderness. When a new family moves in across the lake, she takes a job babysitting their young son. Through this job, she seeks a sense of belonging and adult approval, particularly from her employer.

Paul is a four-year-old boy who moves into the house across the lake from Linda. He is highly imaginative, spending hours building a pretend city on Jupiter's moon called Europa, but he also displays a fearful, clingy disposition and a noticeable physical frailty. He carries around an old, rotting leather glove that he calls his "Thirdhand Man" for survival.

Patra is a 26-year-old mother who recently moved to the isolated lake house with her son, Paul. She spends her time editing a manuscript for her absent husband, Leo. Lonely and seeking companionship in a new town, she hires Linda as a babysitter and treats the teenager as a confidant, blurring the lines between employer and friend.

Leo is Patra's 37-year-old husband and Paul's father. An accomplished cosmologist and strict Christian Scientist, he maintains absolute control over his household's ideology and routines. He projects a powerful demand for facts and logic, aggressively correcting others and changing the atmosphere of a room the moment he enters.

Mr. Grierson is a tanned teacher from California who wears a gold hoop earring and brings an energetic teaching style to the dull school environment. He favors specific students and seeks constant validation for his teaching methods. His behavior often blurs professional boundaries, causing rumors to circulate among the student body.

Lily is a beautiful classmate of Linda who lives in a trailer near the reservation. She holds a strange power over her peers through her quiet demeanor and the rumors that constantly surround her. She seems comfortable being the center of attention and deliberately cultivates an air of mystery by rummaging through the lost and found for distinct items.

Linda's mother is a former hippie and cynical Christian who raises her daughter in an abandoned commune. She frequently acts shocked by the passage of time or the reality of their isolation. She struggles to understand her practical, serious daughter, constantly wishing Linda would act like a normal child and play pretend.

Linda's father is a quietly kind but largely absent presence in the commune. He spends most of his time drinking or riding his all-terrain vehicle through the woods, leaving the parenting responsibilities and emotional labor to his partner.

Rom is a mechanic who dates Linda during her adulthood in Minneapolis. He tries to establish a healthy, committed relationship with her, often urging her to change her isolated habits. He attempts to understand her deeply guarded past but is met with heavy resistance when he accurately analyzes her emotional state.

Lily's father is a heavy drinker who lives in a trailer near the reservation. When Linda arrives looking for Lily, he is heavily intoxicated and struggles to follow her words or remember her visit.