In this Maupassant story, the writer of the diary that forms the basis for the story becomes convinced that he is haunted by—or even controlled by—an invisible creature called a Horla. Part of the action of the story is to record his slow descent into madness as he encounters people who seem to suffer as he does—such as the woman who, under hypnosis, shows up to borrow 5000 francs—or witnesses events that defy explanation, as when he sees a rose detach itself from a stem as if an invisible hand had done so. The man becomes increasingly agitated and begins to construct elaborate theories to explain these phenomena. His obsessive fear of the Horla comes to dominate every facet of his life. He is determined to kill it but realizes that the only way to be rid of it is to kill himself.