From The Art and Popular Culture Encyclopedia
"Relating the advent in France of an invisible being who lives on water and milk, sways the minds of others, and seems to be the vanguard of a horde of extra-terrestrial organisms arrived on earth to subjugate and overwhelm mankind, this tense narrative is perhaps without peer in its particular department."
The story has been cited as an inspiration for Lovecraft's own "The Call of Cthulhu", which also features an extra-terrestrial being who influences minds and who is destined to conquer humanity.
In the form of a journal, the narrator conveys his troubled thoughts and feelings of anguish. All around him, he senses the presence of a being that he calls the "Horla". Throughout the novel, the main character's sanity, or rather, his feelings of alienation are put into question as the Horla progressively dominates his thoughts. The presence of the Horla becomes more and more intolerable to the protagonist, to the point that he is ready to kill either the Horla, or himself. In the end, he has decided to take his own life.
Many think that the author himself was insane when he wrote this novel, but it was only later in Maupassant's life that he was diagnosed with a mental illness. The seeming insanity and dementia of the protagonist contribute much to the fantastic air that pervades the novel.
- The movie Diary of a Madman is loosely based on "Le Horla".
- The Star Trek episode "Wolf in the Fold" features a horla-like entity.
- The Bartimaeus Trilogy features horlas as powerful spirits.
- "Le Horla" is used as an extension of the plot in the short story "The Theater Upstairs" by Manly Wade Wellman.