Into the Darkness maps the long nineteenth century and early twentieth century through its most unsettling imaginative terrains: haunted houses, revenants, occult knowledge, psychological fracture, urban menace, and the porous boundary between rationality and terror. Its range extends from Gothic romance and sensation fiction to ghost story, decadent fantasy, cosmic horror, satire, and proto-science fiction. Canonical landmarks of the supernatural tradition stand beside neglected curiosities, allowing spectral visitations, cursed objects, doubles, and inexplicable encounters to register changing anxieties about modernity, empire, gender, class, and belief. The contributors form an exceptionally broad transatlantic and European constellation, joining major Gothic innovators with practitioners of Victorian realism, French and German fantastic literature, American regional writing, fin-de-siècle decadence, and pulp-era weird fiction. Their diverse social settings and literary inheritances reveal that darkness is not a single mode but a cultural language: domestic unease, colonial dread, religious doubt, scientific speculation, and unconscious desire each receive distinctive expression. Across these voices, the anthology traces the emergence of modern horror from Romantic obscurity to cosmic indifference. Ideal for students, scholars, and general readers, Into the Darkness offers a richly comparative encounter with the traditions that shaped supernatural literature. Its varied forms invite close attention to style and historical context, while the juxtapositions foster illuminating dialogue between psychological, social, and metaphysical visions of fear.