Solomon is an agoraphobic teenager who relies on absolute isolation to manage his severe panic attacks. He spends his days barefoot indoors, coping with his anxiety by watching his father play video games, taking baths, and retreating into science fiction television like Star Trek. Though he tries to convince his parents that he is perfectly content with his reclusive lifestyle, he silently struggles with the limitations of his small world.

Lisa is an ambitious high school junior determined to escape her sleepy, conservative town of Upland. Desperate to avoid repeating the chaotic life cycle of her chronically unhappy mother, she fixates on securing a psychology scholarship at Woodlawn University. She initiates a plan to secretly "cure" Solomon to generate material for a unique college essay, confident in her ability to act as his therapist.

Clark is an attractive, athletic teenager who hides his geeky interests from his jock peers. Unlike his girlfriend Lisa, he is content with his current life and feels no desperate need to leave their hometown. He is deeply loyal and possesses a natural charm that makes him immediately likeable, allowing him to quickly break through social barriers.

Solomon's grandmother is an exuberant woman who serves as a vital source of unconditional support for her grandson. She acts as a persistent symbol of strength from the outside world, bringing joy into the quiet Reed household. She is eager to see Solomon expand his horizons and actively motivates him to step outside his comfort zone.

Valerie is a local dentist and Solomon's mother. She is deeply concerned about her son's agoraphobia and secretly desperate for him to experience a normal teenage life, though she tries to hide this anxiety from him. She eagerly welcomes Lisa into their home, hoping the girl's presence will serve as a catalyst for Solomon's recovery.

Jason is Solomon's father, a man who provides a calm and steady presence in the household. He respects his son's boundaries and allows Solomon to make his own choices regarding his mental health care after earlier therapy attempts proved ineffective for the family.

Janis is a born-again Christian and Lisa's closest friend. She works at the local mall and feels increasingly abandoned as Lisa dedicates her free time to her secret project with Solomon. She serves as a grounding force who frequently questions the morality of Lisa's choices.

Lisa's mother is an overworked woman struggling through a failing third marriage. Her chaotic personal life and emotional distance serve as the primary catalyst for Lisa's intense drive to achieve perfection and leave their town behind.

Ron is Lisa's stepfather, whose unsteady presence in the household contributes to her mother's unhappiness. His eventual departure further destabilizes the home environment that Lisa is so desperate to escape.

Grant is a former childhood friend of Solomon's. Their relationship naturally dissipated shortly after Solomon began homeschooling, leaving the agoraphobic teenager relieved to be free of the pressure to maintain social ties.