Delapore is an older man who grew up on a plantation in Virginia before moving to Massachusetts. Following the tragic death of his only son in the aftermath of World War I, he seeks to connect with his heritage by restoring Exham Priory and proving his family's dark reputation wrong. He is the only human in the household who can hear the strange sounds of rats scurrying within the ancient walls.

Captain Norrys is a plump, level-headed, and amiable young man from the Anchester area. His uncle previously owned the ruined Exham Priory estate, facilitating Delapore's purchase of the property. Despite growing up near the priory and knowing its dark legends, Norrys remains a skeptic who favors practical explanations over supernatural fears.

Black Tom is Delapore's feline companion and a highly perceptive animal. He reacts strongly to the unseen presence in Exham Priory, scratching at the walls and darting through dark corridors in pursuit of phantom sounds. His reactions provide crucial validation to Delapore that the disturbances in the home are not merely imagined.

Thornton is a man devoted to psychic investigation who joins the team exploring Exham Priory. Unlike Norrys, he takes the local superstitions and Delapore's vivid nightmares seriously, interpreting them as meaningful messages from hidden forces. He possesses a deep sensitivity to the atmosphere of the ancient site.

Alfred is Delapore's late son who served in World War I, where he met Captain Norrys. Stationed near Anchester during the war, Alfred learned of his family's mysterious past and shared these stories with his father, ultimately sparking Delapore's interest in reclaiming Exham Priory.

Walter de la Poer is Delapore's ancestor who abruptly left Exham Priory for Virginia in the early 1600s. Local legends claim he fled after violently killing his entire family, an act the villagers supposedly considered justified due to the family's history of unspecified cruelties.