Carlie is a cynical teenager recently placed in foster care after suffering a concussion from her stepfather's physical violence. She uses insults and suspicion as protective armor, actively monitoring the emotional reactions of adults and peers to keep herself safe. She refers to herself and the other foster children as "pinballs," believing they are merely objects bounced from place to place without any control over their own lives.

Harvey is a thirteen-year-old boy coping with two broken legs, an injury he sustained when his alcoholic father ran over him with a car. Nonconfrontational and often lacking the motivation to get out of bed, he distracts himself by compiling lists in a spiral notebook. He daydreams about his mother, who left the family years ago to live on a communal farm in Virginia, holding onto the belief that she will rescue him.

Thomas J is an eight-year-old boy who spent the last six years living in near-total isolation with the elderly Benson twins. Abandoned at two years old, he lacks basic socialization skills and struggles to identify or express his own feelings. Eager to please the adults around him, he views affection as something he must earn by performing helpful tasks.

Harvey's Father is an alcoholic who recently put his son in a wheelchair, claiming he accidentally placed the car in drive instead of reverse. He complains frequently about the responsibilities of parenthood and focuses heavily on how others perceive him. He performs parental concern for police and hospital staff rather than showing genuine care for his injured son.

Carlie's Stepfather is an abusive man who exerts control through violence and intimidation. He gave Carlie a concussion when she refused to tell him where she had been. This act of physical abuse directly led to her removal from the home and placement into the foster care system.

Mrs. Mason is an experienced foster mother who has cared for seventeen previous children before taking in Carlie, Harvey, and Thomas J. Unable to have biological children of her own, she provides a clean and structured environment for her foster kids. She recognizes the defensive mechanisms of the youth in her care and remains patient with their difficult attitudes.

Mr. Mason is a steady and quiet presence in the household who shares the fostering duties with his wife. He connects particularly well with Thomas J, drawing on his own difficult childhood to relate to the boy's struggles with emotional expression. He shares personal stories of his youth, offering empathy and understanding.

The Benson twins are elderly, hard-of-hearing sisters who found an abandoned two-year-old Thomas J outside their home and quietly took him in. They kept him isolated from the outside world, using him primarily as a garden helper. Authorities only discover the boy when the sisters both suffer broken hips and require hospitalization.

Harvey's Mother is a woman who left her husband and son years prior to find her own identity. Harvey idolizes her memory and constantly rereads a magazine article about her commune, holding onto the belief that she will rescue him once she learns of his injuries.

Carlie's Mother is a woman who remains in a household with an abusive man. She is the target of Carlie's persistent, pleading letters asking to return home, representing the familiar, albeit dangerous, life that her daughter wishes to return to rather than facing the unknown foster system.