One significant difference distinguishing Lodge and Crookes from Roy, however, is the level of rigor of their spiritual studies. Even in their own time, Lodge and Crookes were criticized as being overly credulous of psychic claims and blasted as having run shoddy experiments of such claims. Professor Roy, however, was always skeptical and ran very rigorous tests that were often reported in the Scottish media. Perhaps reassured by this rigor, it is said that Roy’s scientific colleagues enjoyed hearing his stories of haunted houses and mediums.

Roy’s serious and calculated approach to testing psychic phenomena is very evident, even delightful to see, in Devil in the Darkness. The researchers in the book are very meticulous, exploring every possible non-supernatural explanation in detail before even considering a possible spirit. For example: when it is suspected that an additional unknown person might be in the house with them, the stranded group devises a plan to search the house, from bottom to top, sealing off and isolating every cleared section as they go. In many inferior horror stories, authors require their characters to do dumb things in order for the terror to proceed; in Roy’s Devil in the Darkness, the characters are almost always making smart decisions, and horrible things happen in spite of their carefulness.

Looking at the dates of haunted house novels given at the beginning of this preface, one notes that many of them appeared in the 1970s, before Roy’s Devil in the Darkness. One can’t help but wonder if Roy read some of these contemporary works, particularly ones with paranormal researchers, and thought to himself in exasperation, ‘I can write something better than these.’

Professor Roy was well-prepared to do so, not only due to his scientific and paranormal experience but also because of his skill as a writer. Devil in the Darkness was his sixth (and, it turns out, final) novel; his first, Deadlight (1968), appeared a decade earlier. His first three books have been characterized as science-based thrillers; the latter three are considered horror. Roy uses his formidable scientific knowledge to develop intriguing and unpredictable plots.