David is the young son of Waknuk's strictest religious leader. He possesses the hidden ability to communicate telepathically with others using thought-shapes. As he meets people outside his community's rigid norms, he begins questioning the oppressive religious doctrine he was raised to follow.

Petra is David's younger sister. Though she initially appears entirely conventional to Waknuk's inspectors, she eventually demonstrates overwhelming telepathic abilities that far surpass those of the older children. She is energetic, highly emotional, and completely unaware of the danger her abilities pose.

Rosalind is David's cousin and a fellow telepath. Recognizing the hostility of the world around her from an early age, she builds a tough emotional armor to protect herself. She is fiercely loyal, deeply capable, and serves as David's closest confidant.

Joseph is David's father and a prominent leader in Waknuk. He enforces the town's strict religious purity laws with zealous fury, readily burning crops and slaughtering animals that fail to meet his standards. He rules his household and community through intimidation.

Uncle Axel is a former sailor who has seen the world beyond Labrador. He acts as a trusted mentor to David, offering alternative perspectives on the nature of God and humanity's past. He provides the children with vital advice and physical protection.

Sophie is a young girl living in isolation with her family on the outskirts of Waknuk. Because she possesses six toes, she is classified as a Deviation and kept hidden from the community. She is sweet-natured and forms a fast friendship with David.

Michael is the most educated and cynical member of the telepathic group. He acts as an information gatherer, relaying facts about the outside world, history, and new methods to the others. He approaches problems with strict logic and strategy.

A woman who lives in a highly advanced, distant civilization. She contacts Petra due to the young girl's extraordinary mental broadcasting strength. She views telepathy as the next step in human evolution and holds the people of Waknuk in low regard.

Mary is David's older sister. She conforms to the expectations of Waknuk society but demonstrates care for David by warning him to keep his unusual dreams a secret. She handles many of the household chores and tends to David after he is punished.

Emily is David's mother and Joseph's wife. She strictly adheres to her husband's puritanical doctrines and demonstrates visible horror when presented with anything deemed blasphemous, even if it involves her own family members.

Elias is David's grandfather, an evangelical who moved from the East to escape what he viewed as progressive society. He established the family's homestead and passed down his harsh, uncompromising religious fervency to his son Joseph.

John is Sophie's father. He lives in constant anxiety about his daughter's safety and remains wary of David's presence, especially given the reputation of David's zealous father.

Mrs. Wender is Sophie's mother. She lives in a state of quiet terror regarding her daughter's physical deviation and pleads with David to keep Sophie's secret hidden from the Waknuk authorities.

Alan is a local Waknuk boy who discovers Sophie's secret. He strictly follows the community's rules regarding deviations and immediately attempts to report what he has found.

Harriet is Emily's sister and David's aunt. When her child is born with a slight deviation, she risks her life to beg her sister for help, believing that a merciful God would not condemn an innocent infant.

Walter is a young boy who shares the telepathic ability. His sudden absence prompts the remaining children to formalize their group and learn each other's names.

Anne is a member of the telepathic group who desperately desires a conventional life. She ignores the warnings of her peers and attempts to integrate into regular Waknuk society by pursuing a traditional marriage.

Rachel is Anne's sister and a fellow telepath. She remains loyal to the group even when her sister distances herself from them.

Sally is a member of the telepathic group who lives near Katherine. She maintains a close bond with her neighbor and helps the group coordinate their survival plans.

Katherine is a telepath who operates closely with Sally. She participates in the group's mental discussions and contingency planning as the danger in Waknuk increases.

Mark is another telepathic youth in the district. He responds to Petra's overwhelming psychic distress calls alongside the others.

Gordon is a leader among the Fringe people and possesses unnaturally long arms and legs. He harbors deep resentment toward Waknuk because his physical deviation cost him his inheritance and standing in the community.

Angus is Rosalind's father and a successful farmer in Waknuk. He frequently clashes with Joseph Strorm over the interpretation of purity laws, often pushing the boundaries of what the community considers acceptable livestock.

Jacob is an elderly farmer in Waknuk. He holds highly traditional, superstitious views and believes that recent agricultural failures are a direct punishment for the community softening its harsh treatment of Deviations.

The local inspector is a government official tasked with determining what is legally human and what is a Deviation. He serves as an authoritative figure who tries to balance strict religious law with practical governance.