Robert Albert Bloch was an American fiction writer, primarily of crime, psychological horror and fantasy, much of which has been dramatized for radio, cinema and television. He also wrote a relatively small amount of science fiction. His writing career lasted 60 years, including more than 30 years in television and film. He began his professional writing career immediately after graduation from high school, aged 17. Best known as the writer of Psycho (1959), the basis for the film of the same name by Alfred Hitchcock, Bloch wrote hundreds of short stories and over 30 novels. He was a protégé of H. P. Lovecraft, who was the first to seriously encourage his talent. However, while he started emulating Lovecraft and his brand of cosmic horror, he later specialized in crime and horror stories working with a more psychological approach.

Horror is a genre of fiction that is intended to disturb, frighten or scare. Horror is often divided into the sub-genres of psychological horror and supernatural horror, which are in the realm of speculative fiction. Literary historian J. A. Cuddon, in 1984, defined the horror story as "a piece of fiction in prose of variable length... which shocks, or even frightens the reader, or perhaps induces a feeling of repulsion or loathing". Horror intends to create an eerie and frightening atmosphere for the reader. Often the central menace of a work of horror fiction can be interpreted as a metaphor for larger fears of a society.