A story that begins with a diary or journal entry “What a wonderful day!” before succumbing to the horrific imagery that will haunt its narrator, Guy de Maupassant’s "The Horla" is about a man who innocently salutes a passing Brazilian ship and (he fears) provokes or invites a supernatural being into his home.  Three days later the narrator begins to succumb to an illness with fevers and chills.  De Maupassant’s protagonist describes this sudden and unwelcome development as follows:

“You might say that the air, the invisible air, is full of unknowable Powers, from whose mysterious closeness we suffer. I wake up full of joy, with songs welling up in my throat. Why? I go down to the water; and suddenly, after a short walk, I come back disheartened, as if some misfortune were awaiting me at home. Why? Is it a shiver of cold that, brushing against my skin, has affected my nerves and darkened my soul?”

From this point on the narrator is a haunted soul, although whether it is entirely in his mind or exists in the real world is uncertain.  “How profound this mystery of the Invisible is!” he exclaims, the source of these terrifying developments unknown.  His once idyllic existence has been replaced by the horrific presence of forces the nature of which he can only wonder about in his new-found despair.  As the story progresses, the narrator’s condition worsens, his symptoms apparently very real as his doctor confirms a rapid heart rate and dilated pupils—but that’s it.  In his journal entry dated May 25, he notes his emotional transformation from happy and undisturbed to sick and perpetually frightened, reduced to looking under his bed and listening for strange sounds.  A vacation away from his home seemingly cures him.

The narrator, his health restored, speaks with a monk while hiking the hills.  The monk explains that the local population claims to be haunted by strange, unpleasant noises, including voices and animal sounds, and some have even claimed to have witnessed an

“an old shepherd, whose head, covered with his cloak, could never be seen; and who led, walking in front of them, a billygoat with a man’s face, and a nanny-goat with a woman’s face, both with long white hair, talking ceaselessly, arguing with each other in an unknown language, then suddenly stopping to bleat with all their might.”

The narrator inquires of the monk whether he believes these stories, and the monk replies that he doesn’t know. He ponders the vast unknowable universe before us, emphasizing the scale of what we don’t know relative to what we think we do know.  The narrator’s condition worsens again and this time he notices water disappearing from his drinking glass.  He describes the terror he is experiencing by writing in his journal,

“Imagine a man asleep, who is being killed, and who wakes up with a knife in his lung, with a death rattle, covered in blood, who can no longer breathe, who will die, and doesn’t understand why—that’s what it’s like.”

The narrator becomes convinced that there is an invisible being haunting his residence, and it is in his journal entry for August 19 that he believes he has found the answer to the mysteries surrounding his illnesses and the terrifying incidences that have plagued his home.  A news article describes frightening developments in Brazil:

“A madness, an epidemic of madness, like the contagious dementias that attacked the population of Europe in the Middle Ages, is raging now in the province of Saõ Paulo. The inhabitants, distraught, are leaving their houses, deserting their villages, abandoning their crops, claiming they are pursued, possessed, ruled like human livestock by invisible but tangible beings, sorts of vampires, which feed on their life while they sleep, and which drink water and milk without seeming to touch any other food.”

The story reaches its climax when the narrator draws a connection between that Brazilian vessel he had innocently saluted months before on the banks of the Seine and the terrifying experiences to which he has been subjected since that fateful day.  Mankind, he concludes, has been taken over by a demon, probably meaning Satan: “He has come . . . the One anxious priests had exorcised . . . We are cursed.  Mankind is cursed.”  The “Horla,” he believes, is haunting him.  His recourse is to burn down his house, taking with it the invisible demon that has possessed it and anyone who enters.  But he reasons that the demon is certainly not susceptible to such easy elimination and most certainly would survive the flames.  As he contemplates the nature of this evil presence and of the fate of mankind, he realizes that if he himself is possessed then death is his only recourse: “No … no … of course not … of course he is not dead.… So then—it’s me, it’s me I have to kill!”  And the story ends.

De Maupassant leaves uncertain the nature of the haunting his narrator has experienced.  Stories of demonic possession have existed for hundreds of years.  Left open, however, is the possibility that this has all been in the mind of the narrator.  As Dr. Marrande writes, “I do not know if this man is mad, or if we are both mad … or if … if our successor has actually arrived.”  It is up to the reader to decide whether Satan exists and functions in the manner described, or whether the haunting the narrator experiences is entirely a product of his psychological deterioration.