A solitary, resourceful young man in his mid-thirties who lives in an endless, sea-soaked labyrinth he calls the House. Operating as a dedicated scientist and explorer, he meticulously catalogues the environment, calculates complex tidal patterns, and tends to the bones of the dead. He experiences significant memory gaps regarding his past, relying entirely on his physical journals to document his existence.

A well-dressed, pragmatic man who appears in the labyrinth twice a week to conduct esoteric rituals. He relies on modern technology like a shining device rather than pen and paper, and fears the rising tides of the House. He acts as the narrator's sole friend and provider, while relentlessly pursuing ancient, hidden powers.

A resourceful police officer investigating a disappearance case that leads her to the labyrinth. Described as having an elfin face, she operates independently and communicates via notes left on the pavement. Her presence introduces a disruptive new element to the isolated world of the House.

An older academic and transgressive thinker who originally discovered the portal to the labyrinth. He possesses extensive knowledge about the House, its origins, and the dead who reside there. He views the structure's statues as embodiments of ideas from another world and maintains a manipulative, charismatic influence over those who follow his work.

A poet and filmmaker who previously studied mathematics and anthropology. She worked closely with a prominent academic and created a film called 'Castle' that featured flooded basements and statues, directly reflecting the architecture of the labyrinth.

A man who spent two years lost in the labyrinth, an experience that left him mentally fragile. After surviving the House, he eventually finds work as a caretaker for a large building, though his descriptions of his ordeal perfectly match the grand architecture of the labyrinth.

A police officer working in London. He is practical and observant, noting the difficult working style of his colleagues while maintaining respect for their effective negotiation skills.

A woman contacted regarding a book project who becomes concerned when the author vanishes, prompting a police investigation.

An individual mentioned in the older, forgotten journal entries. The discovery of his name helps trigger the realization that the journals contain information entirely unknown to the present narrator.

A long-dead king whose name is used in ceremonial magic. His identity forms part of the ancient, arcane history that visitors to the labyrinth attempt to access.