“The Post-Modern Prometheus” tells the story of a mutant man with a giant head and a Cher obsession who bears a resemblance to a comic book monster called the Great Mutato. When the local townspeople turn on the gentle mutant, Mulder and Scully whisk him away . . . to the safety of a Cher concert. In a fantasy sequence ripped straight from the pages of a comic book, the mutant is pulled onstage to dance with Cher (or rather an actor playing the performer, who is seen only from the side and behind) as she sings “Walking in Memphis.” For a fleeting moment we glimpse Mulder and Scully in as romantic a pose as we had ever seen them, close- dancing with goofy, beatific smiles on their faces. It was a perfect moment of fan wish fulfillment, and one that was totally accidental. Chris Carter explains how it came to be.

The inspiration for the episode came from two celebrities who were interested in doing the show, Roseanne Barr and Cher. The episode was written with both of them in mind; Roseanne would have played the mom. Unfortunately, neither came through in the end, so we ended up using a celebrity impersonator in the scene and casting an actor as the mom.

In the scene where Mulder and Scully dance at the end, I was focused on getting the staging right with the Cher impersonator. I knew that Mulder and Scully only had to be her audience, so I kind of left them alone.

When the scene got rolling we had a huge auditorium full of rowdy fans, and there were lots of distractions. One of them was a kid I had spotted in Los Angeles and then cast to play a character named Booger. He turned out to be great, but at that moment either he had had it with shooting or he just wanted to bust out—he started throwing gang signs! I was focused on getting him to stop doing that so I could use the footage.

I had all these distractions and other things I was focused on, and at some point David and Gillian got up and started to dance. They just did it because they were enjoying themselves. Up until this point on the show, we had gone out of our way to keep Mulder and Scully professional and not to have them romantically involved. As much as we kind of flirted with those things, we had not seen them quite that lovey-dovey. It wasn’t scripted; it was one of these moments that just came together on its own.

– Chris Carter as told to Joy Press

Excerpt from Entertainment Weekly’s The Ultimate Guide to The X-Files, celebrating 25 years of out-there conspiracies. On sale Jan. 5, buy it here now.