No in- or out-of-print book has the same goals, content, wide range, and scholarly approach as the present study. Whether intentionally or unintentionally, previously published books have neglected ancient Graeco-Roman texts that either cause horror or may be said to belong to the horror genre. This may partly be the result of the low esteem in which any text that did not fit neatly into one of the major and traditional literary genres was held by most scholars – particularly apparent with regard to texts that dealt with the supernatural or the occult, which were often relegated to specialists in ancient religions, rituals or beliefs. This book reviews the concepts of horror (literary, psychological, and biophysical), examines the current definitions for ‘horror fiction’, evaluates the current interest in the darker side of the classical world, and suggests new ways of thinking about horror as a genre.