"The Horror of the Heights" is a short story by Arthur Conan Doyle. It was first published in Strand Magazine in 1913. The story is told through a blood-stained notebook discovered on the edge of a farm in Withyham. The notebook is written by a Mr. Joyce-Armstrong, and the first two and last pages are missing; the notebook is thus dubbed the "Joyce-Armstrong Fragment". The story has appeared in a number of collections, the earliest being Danger! and Other Stories (1918), as well as in more general collections like Volume 5 of The Road to Science Fiction.