The exploits of FBI Special Agents Fox Mulder and Dana Scully who investigate X-Files: marginalized, unsolved cases involving paranormal phenomena. Mulder believes in the existence of aliens and the paranormal while Scully, a skeptic, is assigned to make scientific analyses of Mulder's discoveries that debunk Mulder's work and thus return him to mainstream cases.
After a doctor loses control and kills a patient on the operating table, Scully hypothesizes that it's linked to work-related stress, while Mulder is convinced of a more sinister reason. After he finds a link between the victim and the four witches Sabbaths, he suspects that a nurse may be practicing witchcraft.