A mysterious lodger arrives at a London boarding house during the height of the Jack the Ripper murders, sparking suspicion and terror in his landlady. Mrs. Bunting, the proprietor of the house, finds herself caught between her financial need for a tenant and her growing, gnawing dread regarding the man's nocturnal habits. As the city remains gripped by the serial killings, the narrative focuses on the psychological tension within the domestic sphere. The story unfolds through a third-person perspective that emphasizes the claustrophobic atmosphere of the Bunting household and the mounting paranoia of the era.

Readers and critics frequently note the effectiveness of the book's slow-burn approach to suspense. Discussion often centers on the shift in focus from the killer to the domestic anxiety of those surrounding him. Many highlight the author's ability to maintain tension without relying on excessive gore or graphic violence. The work is often cited for its influence on the psychological thriller genre and its nuanced portrayal of Victorian social dynamics. This classic remains a point of interest for those examining the evolution of crime fiction.