This anthology assembles a collection of unsettling narratives that explore the thin boundary between the rational world and the encroaching supernatural. Robert Aickman, acting as editor, curates a selection of tales that prioritize psychological unease and atmospheric dread over conventional jump scares. The protagonists in these stories often find themselves isolated or confronted by inexplicable phenomena that defy logical explanation. Through a variety of narrative voices and historical contexts, the collection examines the fragility of human perception when faced with the unknown.

This anthology is regarded as a significant entry in the Fontana series, reflecting the specific editorial sensibilities of Robert Aickman. Readers often note the inclusion of both canonical ghost stories and more obscure, experimental pieces that broaden the scope of the genre. The collection is frequently cited for its commitment to the 'strange story' tradition, which favors ambiguity and psychological depth. It serves as a bridge between the classic gothic tradition and the evolving horror sensibilities of the twentieth century. The variety of authors included ensures a broad spectrum of tone, ranging from the Victorian gothic to the more clinical, modern approach to the uncanny.