The X-Files is an American
science fiction horror drama television series created by
Chris Carter. The program originally aired from September 10, 1993, to May 19, 2002, on
Fox, spanning
nine seasons and 202 episodes, before returning with a
film in 2008, and a six-episode
tenth season in 2016. The series revolves around
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 to debunk his 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 the end of the series. In addition to the series-spanning
story arc, "
Monster-of-the-Week" episodes form roughly two-thirds of all episodes.