Genie is an observant and highly sensitive 11-year-old boy from Brooklyn. He constantly writes questions in a notebook, relying on the internet or patient adults for answers. He keenly observes the emotional states of his family members and worries heavily about his parents' marital struggles as he adjusts to rural life.

Ernie is Genie's 13-year-old brother, who projects a confident exterior. He frequently wears sunglasses and practices karate to impress girls. Despite his confident facade, he is highly self-conscious and puts intense pressure on himself to model bravery for his younger brother.

Brooke is a former military sharpshooter who has lost his sight to glaucoma. Refusing to leave the house due to a fear of disorientation, he maintains a strict sense of independence and carries an unloaded revolver. He spends his time in a specialized sunroom filled with caged barn swallows, mourning the loss of his son and his previous identity.

Tess is an energetic local teenager who lives down the hill from the boys' grandparents. She makes and sells bottle cap earrings at the flea market. Industrious and relatively unsupervised, she serves as a guide for the boys in their new rural environment.

Wood is Genie and Ernie's deceased uncle who died in the Desert Storm conflict. His memory heavily influences the family dynamic, contributing to the tension between his father and brother. A posthumous recipient of the Purple Heart, his legacy forces the family to evaluate their definitions of bravery.

Genie and Ernie's grandmother is a retired nurse who manages the household and maintains a strict daily routine for her visiting grandsons. She sells fresh peas at the local flea market and provides stability for the family. She reveres the memory of her deceased son while trying to manage her husband's stubbornness.

Genie's father is a Brooklyn firefighter who harbors deep resentment toward his own father. He blames his father for pressuring his brother into the armed forces, leading to an estrangement of nearly a decade. He currently faces significant marital difficulties that he hopes to resolve during a trip away from his children.

Crab is Tess's father and a local bartender who embodies an aggressive, traditional form of masculinity. Coarse and physically imposing, he pays Brooke to use his land for hunting and supplies him with alcohol. He frequently pushes the local boys to participate in traditional rites of passage.

Genie and Ernie's mother lives in Brooklyn and is experiencing severe marital tension with her husband. She travels to Jamaica with him to work on their relationship, leaving the boys in an unfamiliar rural environment for a month.

Binks is an eccentric local man who works both as a dentist and as a vendor selling human teeth that he claims bring good luck. His unapologetic weirdness and extreme self-assurance immediately catch Genie's attention at the market.

Tess's mother struggles with severe hypochondria, significantly restricting her family's daily life. She wears face masks and gloves indoors, insists on wiping down everything the boys touch, and covers her furniture in plastic sheets to avoid germs.

Samantha is the family dog belonging to Genie's grandparents. She is part of the daily chore routine for the boys, who must clean up her waste in the yard every morning.