The mythology, or mytharc, is the overarching story developed in a series of episodes of The X-Files where Mulder and Scully investigate and expose an international conspiracy by an organization known as the Syndicate to develop a human/alien hybrid and suppress knowledge of the existence of extraterrestrials who plan to colonize Earth.
Common themes include:
- The continuation of the X-files as well as Mulder's and Scully's assignment to the X-Files Unit
- Revelations about the Mulder and Scully family
- The presence of black oil, Alien Bounty Hunters and/or the Syndicate
- Deaths of, or betrayals by, key supporting characters
It should be noted that some key mythology characters also appear in Monster of the Week episodes; notably, Deep Throat, X and the Cigarette Smoking Man each appear in episodes which involve government activities. Furthermore, as his role expanded, Walter Skinner appears in more Monster of the Week episodes.
This list of mythology episodes is taken from official sources, The X-Files Mythology range of DVDs and the book The Complete X-Files: Behind the Series, the Myths and the Movies. Differences between the DVDs and the book are shown, where appropriate.
- Season 1:
- Season 2:
- Season 3:
- Season 4:
- Season 5:
- The X-Files: Fight the Future (feature-length film set between Seasons 5 and 6)
- Season 6:
- Season 7:
- Season 8:
- Season 9:
- Season 10
- Season 11