The X-Files is coming back to the small screen 13 years after it finished its almost ten year on TV. The show gained a loyal group of fans affectionately called (X-Philes) and won 16 Emmy awards for making people “Want to Believe” but to no surprise a show that is based on mystery, has a few unknown facts about itself.

20. The Theme Song was based on The Smiths 1985 anthem “How Soon Is Now” but instead of focusing on the hook, the show’s music composer Mark Snow used Morrisey’s small whistling part. Resulting in one of the most chill inducing, hair raising theme songs ever. The theme song was also remixed by an Italian producer creating an odd dance track that ended up reaching Number 8 on the UK charts.

19. Gillian Anderson was almost replaced as Scully because Fox executives were adamant she wasn’t enough of a “bombshell.” The show’s creator Chris Carter felt otherwise and cast Anderson even though she had only been on screen once before filming the pilot episode.

18. Chris Carter came up with the idea for the show after reading a report that stated 3.7 million people claimed they had been abducted by aliens. One of the main inspirations for the show ended up being the 1970s series, Kolchak: The Night Stalker.

17. In the show Agent Mulder is a believer while Scully is a skeptic, however in real life it is David Duchovny who is a skeptic and Gillian Anderson who believes.

16. Since filming in Vancouver made a desert hard to come by, production teams had to spray over 1600 gallons over a disused quarry to recreate the look of New Mexico. They later added in a clearer sky digitally.

15. Speaking of location, the show was filmed for five seasons in Vancouver because L.A. lacked the creepy, forest background that many of the episodes needed, so Carter moved the who show to “where the good forests are.” However after season 5 Duchovny forced the whole show back to L.A. so that he could be closer to his then wife, Tea Leoni.

14. The Cigarette Smoking Man played by William B. Davis was only supposed to be an extra but went on to become one of the most iconic bad guys in TV history, producers had no intention of him becoming the main antagonist of the show.

13. In fact The Cigarette Smoking Man (Davis) hadn’t smoked a cigarette in 20 years before taking the role, and took it up again for two seasons before thinking better of it and switching to herbal.

12. The agents FBI badges don’t actually say Federal Bureau of Investigation, instead they read “The Federal Bureau of Justice, United States Department of Investigation because it is illegal to fake an FBI badge.

11. Unsurprisingly Anderson’s Agent Scully was created after The Silence of the Lambs FBI Agent Clarice Starling played by Jodie Foster. In fact when the sequel rolled around and Foster did not reprise the role, producers wanted Anderson. Unfortunately her X-Files contract had a clause preventing her from playing any other FBI agent on screen.

10. The show was the big break for Breaking Bad creator Vince Gilligan. As a huge fan, and a young writer, Gilligan sent a script into the show which was made into an episode in season 2. He was then hired and wrote 26 more episodes and has 44 co-executive producer credits on The X-Files.

9. The plot of the first Final Destination film was first submitted as a script for one of the show’s episodes. Carter wasn’t sold on the script submitted by screenwriter Jeffrey Reddick about a real woman who didn’t get on a plane because of a feeling her mother had, and the plane ended up crashing. Others did like the script however and it was turned into the movie Final Destination.

8. They worked David Duchovny’s embarrassing Celebrity Jeopardy appearance into the show. After not doing well on the game show, the writers began referencing different things that he got wrong such as when Scully is reading “Breakfast at Tiffany’s” and eventually Jeopardy host Alex Trebek makes an appearance in episode 20 of season three.

7. Anderson had to stand a box for many of the scenes between herself and Duchovny because their nearly foot height difference made it extremely difficult to frame a close shot of the two.

6. The episode “Home” from season four was the first to include a viewer discretion warning for graphic content. The episode contains a scene where the mother who is a quadruple amputee is pulled out from under a bed, which was inspired from a real story in Charlie Chaplin’s autobiography. Chaplin claimed he and his family were staying in a tenement home where they discovered a quadruple amputee under the bed.

5. Season four, episode 12, “Leonard Betts” was the highest-rated episode of the series with 29.1 million people watching. Its record high was due in part to airing after Super Bowl XXXI.

4. Having started in 1993 and running until 2002, the show had numerous cameos by now household names. Ryan Reynolds, Jack Black, Shia La Beouf as well as many others all appeared but one of the most random was Foo Fighter frontman Dave Grohl who appears for only a few seconds during Season 3’s “Pusher” episode. Grohl still refers to it as “his acting debut.”

3. The Smithsonian’s National Museum of American History has many of the show’s items including the “I Want To Believe” poster and the agent’s FBI badges.

2. David Duchovny sued 20th Century Fox before season 7 because he believed they had undersold the rights to the show to their own affiliates, in turn costing him lots of potential money.

1. After working together for so long, Duchovny later revealed that he and Anderson actually couldn’t stand each other many times on set. “Familiarity breeds contempt” he said, but also said it was nothing personal, just too much time with the same person.