In conventional detective fiction a supernatural element is usually introduced as a ruse, but in these stories various psychic sleuths are confronted by eerie mysteries whose solutions arise from their supernatural aspects. Many of these occult detectives - such as Dennis Wheatley's Neils Orsen, and E. and H. Heron's Flaxman Low - were based on actual persons. W. H. Hodgson's sleuth, Carnacki, applies scientific principles to occult techniques. Arthur Machen's "The Shining Pyramid" offers what may be the most intriguing use of cryptography after Poe's "The Gold Bug. "