Adam is an anxious but determined teenage boy who decides to ride his bicycle to a hospital in Rutterburg to visit his father. He fears dogs, windowless spaces, and the outside world in general, relying on the nursery rhyme "The Farmer in the Dell" to calm his nerves. Concurrently, he sits through taped interview sessions with a man named Brint in an institutional setting, trying to answer difficult questions about his fractured memories.

Dave is Adam's father, an insurance agent who works in a soundproof basement office. He maintains a seemingly routine suburban life complete with a Rotary Club membership and a reliable car. He shares a quiet bond with his son over a mutual love of literature and books, masking deeper anxieties about his family's safety.

Louise is Adam's mother, a withdrawn and cautious woman who rarely leaves the house. She maintains no local friends or professional commitments, viewing the outside world with intense suspicion. She devotes herself entirely to her family but carries an unmistakable aura of grief and fear.

Brint is an evasive interviewer who questions Adam inside a clinical facility. He prefers wearing business suits over medical coats and describes himself merely as a guide through Adam's fractured memories. He routinely presses Adam for specific details regarding Mr. Grey and his parents, showing little concern for Adam's physical discomfort during the sessions.

Amy is an outgoing and confident teenage girl who dates Adam. She possesses a bold sense of humor and frequently orchestrates elaborate pranks that she calls "Numbers," such as abandoning filled carts in grocery stores. Her lively presence provides a sharp, joyful contrast to Adam's profound shyness.

Mr. Grey is a shadowy figure who conducts closed-door meetings with Dave in the family's basement office. While Dave refers to him as an insurance supervisor, he operates with intense secrecy and occasionally utilizes different names. He exerts a commanding influence over the household, acting as a source of intense stress for Louise.

Whipper is an aggressive older teenager who travels around in a car with his two friends. He actively seeks out conflict with vulnerable targets and decides to harass Adam, repeatedly demanding to know what is inside the package Adam carries on his bike.

Dobbie is a teenage boy who travels closely with Whipper. He acts as an intimidating presence, backing up his friend's aggressive behavior toward strangers.

Lewis is the third member of a hostile group of teenagers. He rides along as they follow and physically harass Adam during his trip.

Arnold is a kindly older driver who spots Adam in distress on the side of a country road. Overruling his wife's objections, he stops his vehicle to physically pull Adam out of the mud and offer him a safe ride.

Edna is a cautious, ailing woman traveling with her husband. She voices strong disapproval of picking up strangers, believing firmly that people should mind their own business to stay safe.

Arthur is a large-bodied local resident who observes the street from above. When someone steals Adam's bicycle, he offers information about the thief's identity in exchange for a reward.

Junior is a boy who opportunistically steals an unattended bicycle outside a drugstore. He reacts aggressively when confronted but ultimately loses the physical struggle for the bike.

Martha is a nun living in a convent. She serves as Louise's only living relative and speaks to her once a week by phone, providing Louise with a rare connection to the world outside.

Dr. Dupont is a medical professional who wears a white coat and oversees patient care at the facility where Adam resides. He interacts with Adam gently but avoids answering direct questions about Adam's family.

Mr. Harvester works as the maintenance person at the medical facility. He greets residents casually as he goes about his daily upkeep of the grounds.

Luke is the switchboard operator who manages communications at the institutional facility where Adam stays.

Silver is a German shepherd dog that lives at the medical facility. Though described by Brint as a good animal, the dog triggers intense fear in Adam due to a past traumatic encounter.