The X-Files is undoubtedly one of the most successful science fiction TV shows ever, but even the best series have to end, and for The X-Files, its (initial) expiration date came following the season 9 finale. The Fox sci-fi drama, created by Chris Carter, premiered in September 1993 and was a hit among critics and audiences alike. Its ratings only grew as the seasons passed, which is quite uncommon for network TV, and The X-Files soon became known as one of the quintessential series of the 1990s and one of the best sci-fi shows of all time.

The X-Files followed the partnership between two FBI agents — Fox Mulder and Dana Scully (played by David Duchovny and Gillian Anderson, respectively) — as they investigate unsolved cases involving the paranormal, which were appropriately called “X Files.” While Mulder passionately believes in the supernatural, Scully is a skeptic who relies on science to discover the truth. Critics praised the chemistry between Duchovny and Anderson, and Mulder and Scully’s relationship is frequently referenced as one of the best TV duos ever. Despite its established place in TV history, Fox still canceled The X-Files after season 9.

The X-Files Suffered A Ratings Slump In Season 9

The Fox Show’s Ratings Decreased Dramatically

Even though The X-Files contained unbelievable storylines and fascinating characters, the sci-fi series started to nosedive after season 8. Whereas season 8 averaged about 14 million viewers per episode, The X-Files season 9’s ratings dramatically dropped to an average of nine million audience members. A drop of five million is considerable and indicated that viewers weren’t as passionate about the show as they used to be. Critics gave The X-Files season 9 negative reviews, and fans made it known that they were upset with the story direction, which many found to be convoluted.

Due to the negative reaction, the sci-fi series’ viewership totals decreased significantly. Of course, numerous other factors played a role in The X-Files season 9’s poor ratings. However, the network was unwilling to give the TV show a second chance and Fox canceled it before the season 9 finale aired in 2002.

Other Problems The X-Files Season 9 Faced

David Duchovny Exited The X-Files After Season 8

Aside from its bad ratings, the season 9 episodes of The X-Files suffered because David Duchovny exited the series after the season 8 finale. Duchovny had sporadically appeared as Mulder throughout season 8. However, the actor decided to officially leave the show before season 9 premiered in November 2001. Gillian Anderson tried to hold The X-Files up on her own, but part of what made the sci-fi series so exceptional was the dynamic between Mulder and Scully. Without one of them, the show just doesn’t work, as proven by its decline in ratings and quality in season 9.

Some (including members of the cast and crew, including creator Chris Carter) credited the September 11 attacks as a reason why The X-Files experienced a drop in ratings. However, Duchovny’s absence and the confusing and uninteresting story ultimately sunk the show’s ship. Thankfully, Duchovny returned as Mulder during the X-Files season 9 finale (which doubled as the series finale) to wrap up his character’s story. However, the X-Files‘ original series finale in 2002 wasn’t the last time fans would see Mulder or Scully.

The X-Files Eventually Returned (Twice!)

Mulder & Scully Returned For A Movie & A Revival

The X-Files season 9 finale evidently wasn’t the end for Mulder and Scully as they returned in the 2008 supernatural thriller film The X-Files: I Want to Believe. The movie received mixed reviews as critics celebrated David Duchovny and Gillian Anderson’s chemistry but found fault with the plot. Almost eight years later, Fox revived the sci-fi show, and Duchovny and Anderson reprised their roles as Mulder and Scully once again. Fox produced two extra seasons of The X-Files, bringing its official total to 11, but there’s seemingly always the possibility for more Mulder and Scully stories.