Warning! This post contains spoilers for the Wednesday, January 24 episode of The X-Files. Do not read this until you've watched the hour.

The X-Files took on the Mandela Effect and President Trump (via a Trump-like alien) in Wednesday’s “The Lost Art of Forehead Sweat.” But thanks to Reggie Something (Brian Huskey) insisting he was really Scully (Gillian Anderson) and Mulder’s (David Duchovny) long-lost partner, the hour ended up being, in many ways, a love letter to the series itself.

As Reggie explained his “real” connection to the dynamic duo, viewers got an alternate take on things: new opening credits with Reggie and Reggie in the background (adding snark) to memorable scenes throughout the series—including Mulder and Scully’s first meeting.

Deciding which moments to include wasn’t exactly easy—for an unexpected reason. “The problem with that was the scenes I thought I was going to use, the famous scenes, didn’t really work with fitting another person in. They were tight close-ups between David and Gillian,” episode writer Darin Morgan explains with a laugh.

He continues, “Where would I put the character? That was the last thing I wrote. I was skimming through [old] episodes going, ‘OK, he could fit in there. People remember this scene or this character, and Reggie could be put into this scene.’ It was a combination of which episodes die-hard fans would remember and if the character would fit in there. It’s a bit arbitrary, but I got the main ones I wanted in.”

There was one memorable scene Morgan tried to work into the montage, but couldn’t quite fit. “I wanted to fit another one of [series creator] Chris [Carter]’s in,” Morgan says. “[From Season 5’s] ‘Post-Modern Prometheus,’ I wanted to fit t he [end scene with them] dancing in. I wanted him dancing in the background, but he didn’t fit in there.”