Nearly all Conrad's fictional works in which Marlow is a narrator and observer of events could be considered related titles, with "The Secret Sharer" (1912; see separate entry) being an obvious parallel, since that story also reveals something of the hidden nature of the human capacity for crime. It has been noted that Axel Heyst of the novel Victory (1915; see separate entry) shares some affinities of character with the Count, since both seek to withdraw from human suffering and human involvement in order to create a more controlled and "reasonable" existence for themselves.

Conrad's world of urban crime in The Secret Agent (1907; see separate entry) is located in London rather than Naples, but its depiction of an underworld of anarchists and petty criminals provides a parallel to Conrad's depiction of the undercurrent of violence and crime in the supposedly serene world of Naples.