"Demons" is the twenty-third episode of the fourth season of the American science fiction television series The X-Files. It premiered on the Fox network in the United States on May 11, 1997 and in the United Kingdom on BBC One on . It was written by R. W. Goodwin and directed by Kim Manners. The episode helps explore the series' overarching mythology. "Demons" received a Nielsen rating of 11.8, being watched by 19.1 million viewers in its initial broadcast. The episode received mostly positive reviews from television critics, with many complimenting the episode's look in Mulder's mind. The show centers on FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) who work on cases linked to the paranormal, called X-Files. Mulder is a believer in the paranormal, while the skeptical Scully has been assigned to debunk his work. In this episode, Mulder wakes up in a hotel with blood all over him and no memory of what happened. Mulder and Scully soon discover that Mulder was involved in a double homicide and may have been the killer. It is soon revealed that Mulder had been seeing a doctor who had allowed him to view glimpses of his past memories. After evidence becomes paramount, Mulder is cleared of the murder charges. The episode was written by R. W. Goodwin, an executive producer and director for the show. This marked the second instance where a member of the production crew wrote an episode, after the third season entry "Wetwired", written by Mat Beck. The episode was influenced by An Anthropologist on Mars, a series of essays by Oliver Sacks, in particular The Landscape of Dreams featuring a man who could recall every detail of his childhood. During the flashback sequences in the episode, various effects were created by manipulating the camera and its film. Plot Fox Mulder's (David Duchovny) mind flashes back to being in the attic with his sister Samantha while their parents are arguing downstairs. Back in the present, Mulder wakes up in a hotel room in Providence, Rhode Island, covered in blood. Mulder calls Dana Scully (Gillian Anderson), who arrives, finding him in shock. Mulder has a pounding headache and has no memory of what he has done in the past two days. Scully finds that two bullets have been fired from Mulder's gun and that he has keys belonging to a David and Amy Cassandra.