Following the funeral of Simon Cordier (
Vincent Price), a French
magistrate and amateur sculptor, his secret diary is read out by Simon's pastor friend to a group of people gathered around the table, Simon's servants, and a police captain. The diary reveals that Simon has come into contact with a malevolent entity. The invisible yet corporeal being, called a
horla, is capable of limited
psychokinesis and complete mind control. It is implied that Cordier's particular horla is one of a whole race of evil beings which devote themselves to driving humans insane. Cordier first interacts with the horla when he meets a prisoner whom the entity drove to murder four people. The horla possesses the inmate and attempts to kill Cordier, who in self-defense accidentally kills the man. The magistrate inherits the prisoner's troubles as the horla turns its hauntings toward him. As the horla begins to destroy Cordier's life, he fears he is going mad and seeks help from an
alienist, who suggests that he take up a hobby. Cordier chooses to pick up his old interest in sculpture, meeting a model along the way. The model, a local woman by the name Odette Malotte, is already married. Wanting a better life, she claims to love Cordier and he pledges his love to her in turn. The horla insists the model is not the charming jewel that Cordier sees, but instead a conniving gold-digger, and compels Cordier to treat her as such. This sets up a conflict in Cordier, that he might not be the astute judge of character that his title indicates. In an episode of insanity, Cordier murders Odette with a knife. Her decapitated body is found in the river, but her husband (not Cordier) is blamed for the crime. As his and others' lives are put in jeopardy, he becomes convinced of the horla's existence and decides drastic measures are needed to end its evil. He lures the horla into his house at night. When his presence is felt, Simon hurls an oil lamp towards the curtains, setting the house ablaze. Simon succeeds in destroying the horla, but not without sacrificing himself as the house burns in flames. The film concludes with the people seated around the table after reading Simon's diary. Some believe Simon was mad and that the horla does not exist, others are unsure and believe that the horla might have existed. The priest's opinion is that wherever evil exists, the horla exists. ==Cast==