An unnamed rural Irish scholar with a wooden leg, wholly obsessed with the eccentric thinker De Selby. He commits a botched robbery and murder in pursuit of funds to publish his academic work. Following the crime, he finds himself on a bizarre journey filled with strange encounters, unanswerable questions, and shifting realities.

A strong, ostensibly civil man initially employed by the narrator's late father to work the farm. He is lazy yet opportunistic, eventually taking over the farm's operations and tightly linking his life to the narrator's. Divney convinces the narrator to commit a robbery so he can fund his marriage to Pegeen Meers.

An enormous, red-faced policeman with a silent red mustache and an unnatural, disquieting appearance. He is deeply fixated on bicycles, atomic theory, and unnecessary bureaucratic procedures. He serves as the primary authority figure in the strange parish, subjecting visitors to chaotic questioning.

A wealthy, elderly neighbor who spent fifty years in the cattle trade. He is known to carry a cash box containing a large sum of money. After the crime, he appears in a surreal context, espousing an unusual philosophy about life and language.

A strange, knife-wielding robber and self-proclaimed captain of the one-legged men. Initially threatening the narrator, he changes his tune when they bond over their shared physical trait. He provides directions and becomes an unexpected ally in the unusual environment.

The narrator's soul, functioning as a distinct, conversational entity. Joe is highly imaginative, sensitive, and often critical of the narrator's pretension. He provides running commentary, suggests elaborate aliases, and occasionally takes extreme offense at the narrator's thoughts.

A heavy-fleshed policeman with a high, delicate voice. He is a master craftsman and inventor who creates impossibly small, intricate boxes and reality-bending machines. He takes his duties in the strange parish very seriously, managing the incomprehensible machinery of the region.

A civilian in the parish who is deeply affected by the region's strange atomic theory. Having spent so much time on his bicycle, he has taken on mechanical traits. He must keep moving to maintain his perpendicular balance, lest he topple over.

The enigmatic third policeman of the parish, described by his colleagues as exceptionally eccentric, cranky, and rarely seen. He supposedly lost his mind after viewing a specific color created by MacCruiskeen. He operates out of a hidden, highly unusual station.

An eccentric philosopher, physicist, and writer whose bizarre theories about life and reality form the core of the narrator's academic obsession. Though he does not appear physically, his convoluted ideas dictate the narrator's worldview. His writings provide comfort during confusing trials.

A local woman whom John Divney intends to marry. She serves as the financial catalyst for Divney's criminal plans.

An official who checks in on Sergeant Pluck's precinct. He brings news of a violent crime and questions the unorthodox methods of the local police.

The middle brother of a local family, tasked with building a scaffold. He shares physical similarities with Martin Finnucane and assists the narrator in passing along a message.