| The X-Files | Premise | Crossovers | Episodes | Background |
Crossovers[]
As the first series created by Chris Carter, The X-Files is considered to be the central series of the fictional universe which also includes Millennium and The Lone Gunmen (TV series), and there are several crossovers seen throughout the series.
A character who appeared in both The X-Files and Millennium was fictional novelist José Chung. Chung, first created by writer Darin Morgan for The X-Files episode José Chung's From Outer Space, was also the focus of the Millennium episode "José Chung's Doomsday Defense". The only specific crossover featuring regular cast, however, was The X-Files episode Millennium, in which the story arc of Millennium was finally resolved, following that series' cancellation. The episode featured Frank Black and his daughter, Jordan.
First appearing in The X-Files episode E.B.E., the characters of the Lone Gunmen were later given their own spin-off series, The Lone Gunmen. Featuring appearances from Fox Mulder, Walter Skinner and Morris Fletcher, the series lasted only one season. Like "Millennium" before it, the resolution for the series finale cliffhanger was later shown in the episode Jump the Shark, featuring "The Lone Gunmen" characters of Jimmy Bond, Yves Adele Harlow and Kimmy Belmont.
The season five episode Unusual Suspects also features the character of Detective John Munch. Portrayed by Richard Belzer, the character of Munch is also a regular character of both Homicide: Life on the Street and Law & Order: Special Victims Unit. Following this connection further, all three series of The X-Files, Millennium and The Lone Gunmen are considered to be part of the "Tommy Westphall Universe".
Although The Simpsons was featured in a fictional sense in The X-Files episode The End, an episode of that animated series, entitled "The Springfield Files", included appearances by Agents Mulder and Scully as well as aliens, the Cigarette Smoking Man and FBI Headquarters.
The X-Files featured many other references to films and television series, including Harsh Realm, the only other series created by Chris Carter's Ten Thirteen Productions. Like The Lone Gunmen, Harsh Realm also lasted only one season. Although it did not include any direct references to The X-Files, a scene from the series can briefly be seen playing on a television screen in The X-Files episode Sein Und Zeit, watched by Bud LaPierre, who exclaims while watching the scene, "This is great!" and later recalls, while being interviewed by Mulder, that he had never before heard of the series but that it had been good. The character of Bud Lapierre was portrayed by Mark Rolston, who appeared in Harsh Realm's second episode as a bounty hunter. Furthermore, the movie The X-Files: I Want to Believe includes cameo appearances by Sarah-Jane Redmond, whose character introduces herself as Special Agent in Charge Fossa; the same actress played a recurring character called Inga Fossa on Harsh Realm.
Morley cigarettes, a brand depicted in The X-Files and Millennium, have also appeared in many different films and television series, including Buffy the Vampire Slayer.