Occult detective stories combine the tropes of detective fiction with those of supernatural horror fiction. Unlike the traditional detective the occult detective is employed in cases involving ghosts, curses, and other supernatural elements. Some occult detectives are portrayed as being themselves psychic or in possession of other paranormal powers.
It is difficult to settle on the very first of any fictional character type; however, Fitz James O’Brien’s Harry Escott is a contender for first occult detective in fiction. A specialist in supernatural phenomena, Escott investigates a ghost in "The Pot of Tulips" (1855) and an invisible entity in "What Was It? A Mystery" (1859). The narrator of Robert Bulwer-Lytton’s novella "The Haunted and the Haunters; or, The House and the Brain" (1859) is another student of the supernatural who probes a mystery involving a culprit with paranormal abilities.
Sheridan Le Fanu's Dr. Martin Hesselius appeared in "Green Tea" (1869) and later became a framing device for Le Fanu's short story collection In a Glass Darkly (1872).
The next prominent figure in this tradition was Dr. Abraham Van Helsing in Bram Stoker's Dracula (1897), followed closely by E. and H. Heron's Flaxman Low, featured in a series of stories in Pearson's Magazine (1898–99), Algernon Blackwood's Dr. John Silence, and William Hope Hodgson's Carnacki the Ghost Finder. The adventures of Carnacki have been continued by A. F. Kidd in collaboration with Rick Kennett in 472 Cheyne Walk: Carnacki, the Untold Stories (2000) and by William Meikle in Carnacki: Heaven and Hell (Colusa, CA: Ghost House Press, 2011). Other supernatural sleuths in fiction dating to the late nineteenth century include Alice & Claude Askew's Aylmer Vance and Champion de Crespigny's Norton Vyse.