Diary of a Madman is a 1963 horror film directed by Reginald Le Borg and starring Vincent Price, Nancy Kovack, and Chris Warfield.
The screenplay, written by producer Robert Kent, is an adaptation of Guy de Maupassant's short story "Le Horla" ("The Horla"), written in 1887. Kent's rendition is notably divergent from the source material, especially in relation to the religious and moral themes of the film, which contradict not only those of the short story, but de Maupassant's as well.
^ New York Times, film overview.Synopsis
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 transpires 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.
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