Richard is a disillusioned middle-school teacher and aspiring writer who feels trapped in a deeply unhappy marriage. He harbors lifelong regrets about his lack of courage, particularly his inability to stand up to his older brother or pursue his high school sweetheart. Despite his family acting like strangers under the same roof, he finds solace in his private workspace and his fading dream of becoming a successful author.

Jon is a bright, selfless teenager with a profound talent for electronics and tinkering. He wears thick spectacles and wins science fairs through his mechanical intuition. Neglected by his father, he seeks out a paternal dynamic with his uncle Richard, for whom he builds a custom word processor as a birthday gift just prior to a fatal car crash.

Lina is Richard's bitter, quick-tempered wife who belittles his writing ambitions and blames him for their lack of wealth. She spends her days at home while Richard works as a teacher to support them. She insists on remaining the center of Richard's attention, demanding he hang a photograph of her in his private study despite his obvious distaste for it.

Roger is Richard's older brother, characterized by his intimidating physical presence and history of bullying. He consistently uses his size and aggressive demeanor to get what he wants, demanding submission from those around him. As an adult, he struggles with heavy alcohol consumption and remains entirely indifferent to the needs or accomplishments of his own child.

Seth is Richard and Lina's teenage son. He is rebellious and heavily invested in youth counterculture, spending his time playing guitar rather than focusing on his responsibilities. He views his father with open disrespect, finding Richard's dreams and hobbies pathetic.

Belinda is Roger's wife and Jon's mother. She frequently wears large sunglasses even on cloudy days to hide the physical signs of her husband's abuse. She remains the object of Richard's lifelong affection and represents the alternate, happier life he wishes he had secured for himself.

Nordhoff is Richard's pragmatic neighbor. He recognizes Jonathan's brilliant technical mind but maintains a healthy, cautious respect for unknown or experimental technology. He serves as a voice of reason who prefers to keep a safe distance from strange devices.