The X-Files is an American science fiction horror drama television series. It is part of The X-Files franchise, created by Chris Carter. The program originally aired from to , spanning nine seasons and 202 episodes. The series recounted the exploits of FBI Special Agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) 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. Early in the series, both agents become pawns in a larger conflict and come to trust only each other. They develop a close relationship, which begins as a platonic friendship, but becomes a romance by series end. In addition to the series-spanning story arc, "Monster-of-the-Week" episodes formed roughly two-thirds of the episodes. In such stand-alone episodes, Mulder and Scully investigated strange crimes that had no effect on the show's mythology, though the episodes enriched the show's background.
The X-Files was inspired by shows like Alfred Hitchcock Presents, The Twilight Zone, Night Gallery, Tales from the Darkside and especially Kolchak: The Night Stalker. When creating the main characters, Carter sought to reverse the usual gender stereotypes and made Mulder a believer and Scully a skeptic. For the first seven seasons, the show featured Duchovny and Anderson equally. In the last two seasons Anderson became the star, while Duchovny appeared intermittently, following a lawsuit. New main characters were introduced: FBI agents John Doggett (Robert Patrick) and Monica Reyes (Annabeth Gish). Mulder and Scully's boss, Assistant Director Walter Skinner (Mitch Pileggi), also became a main character. The first five seasons of The X-Files were filmed and produced in Vancouver, British Columbia, but the series eventually moved to Los Angeles, California to accommodate Duchovny.