SPOILER WARNING: Tonight's episode of The X-Files, "Ghouli," discussed at length below.

Fans of The X-Files know that the writing team of James Wong and Glen Morgan has produced some of the creepiest episodes of the series. "Squeeze," "Tooms," "Home" -- they all rank as series classics, which are still referenced with reverence today. The duo actually left to create their own series, Space: Above and Beyond (1996), but remained in the world of Chris Carter shows, writing episodes of The X-Files until 1997, and for the series, Millennium and The Lone Gunmen.

Wong and Morgan also started the Final Destination franchise, co-writing the first and third films, with Wong directing them, as well. The duo separated to pursue their own creative paths in the mid 2000s, and since 2011, Wong's been a writer and co-executive producer on American Horror Story. But his love of Mulder and Scully wooed him back to Season 10, and now Season 11, as a writer/director. And while Morgan and Wong both returned, Wong has flown solo on his episodes penning "Founders Mutation," tonight's "Ghouli," and an upcoming episode in the back five.

"Ghouli" has all the hallmarks of a Wong episode: scares, great character moments, and great tension. We talked with him about the personal experience that inspired the episode, working with Gillian on her emotional apology to William, and more.

First off, after being away from The X-Files for so long, how has it been getting back into the story groove for these two seasons?

James Wong: Well, it wasn't easier because I had this whole stockpile of ideas, because I didn't. It was easier in one respect in that we had just done the six [episodes], they were sort of an appetizer, I would say, to get you into The X-Files, and that was easier for me to get into the whole flow of it, and to get Mulder and Scully's voices. In Season 10, I still didn't quite know who they were when we first started, because it was such a long layoff. In this season, I really felt like I understood who they were now and for that part of it, it was easier for me. But, the one thing I was worried about was what kind of stories are left? But then, as you work through it, it's really a pleasure and it sort of came natural to get the story back.

When I spoke with Glen and Darin Morgan about writing X-Files stories all these years later, they both had unique stories about what inspired their episodes. Did your story come from the monster or from the William of it all?

I was interested in William's story, even from Season 10, because I really felt like I wanted to know what was happening with him. But it was never a thing where we sat down and said, "This is what we need of William." So the story came together for me in the sleep paralysis aspect of it.

I experience that when I nap sometimes. Do you experience it too?

I had experiences while shooting a movie in Mexico. I had this sleep paralysis thing. I really felt a presence in the room in this hotel and I had this persistent dream that I woke up being chased and I fell back in the bed again. So it was a personal experience that I really wanted to explore. Then as I thought more about the story and the first episode [of this season] I came to the idea of using William as the reason why I came up with a monster and how that could lead to a hidden way to reveal William.

Let's talk about the Ghouli monster and where that thing came from?

I really liked the idea of a spider with the multiple appendages. It really does have a very arachnid feel to it. So that's how we started with Bill Terezakis, the makeup effects designer/supervisor.

You've been working on other horror shows like American Horror Story; have your experiences on that show impacted how you write and direct horror on TheX-Files now?

Well, it certainly does on my next episode. You'll see a distinct sort of American Horror vibe to it. Not so much "Ghouli," but the second one, certainly some of the things I've been working on recently kind of connects with The X-Files.

Diving back into the character beats of this episode, let's talk about Scully's incredibly emotional morgue confessional to William. Did Gillian have a lot of thoughts about how to play that?

Gillian was really into that whole idea that it was like an apology but speaking to someone who may, or may not be her son. She liked the idea of baring her soul to this person who she felt like she failed. We talked a lot about that, and we worked on the monologue together. The thing that she kept coming back to was that she was interested in the duality of not really knowing if this was her son, and being overtaken by the emotions of what it would have been like for her. I liked really exploring that and also for her character to explore the idea that when the body is missing, that became a moment of optimism for her. Of course, there's Mulder who's saying, "Well, there could be many reasons..." because there's this conspiracy theory about why the body is missing. But I liked that idea that Gillian was really into Scully's hope of what happened.

That certainly ties into the chimera motif, which underscores everything in the episode including the name of the boat.

Yeah.

Casting the actor to play William is no small thing. What qualities were you looking for in Jackson Van De Kamp/William?

I think Miles was in New York when we were casting, so I saw him on tape. Miles certainly had a quality I really loved, and you'll see what actually happens to his character at the end of the season. He stood out to us. It's that kind of Mulder coolness that he has that made him attractive to me.

Interesting. And he already has the vision connection with Scully. I have to ask is their last minute stop at the gas station an example of that pull so William could see Scully once more?

Yeah, that's exactly right. You sort of hear their last conversation together, as we see it on the monitor. For me, doing the mix on the show, it was really poignant and wonderful, so I'm really happy with it.

You directed and wrote this one, so what were your favorite moments?

I really loved shooting in the boat.

Yes! That is a great set.

That was an amazing set and the crew worked really hard. It was really a messed up place, so they worked really hard cleaning it up so we could actually shoot there. There's asbestos and stuff that we had to clean out before we could go in.

Also, there's a little tiny moment when David is talking to Mitch, or when Mulder is talking to Skinner on the boat. Mulder reveals that it was their son that was killed, and I really loved that. I really loved what Dave did and I really loved what Mitch did in that little moment.

We know, but Mulder doesn't know, that Skinner is working with CSM. Yet Skinner's reaction came across so genuine. Are we allowed to believe in Skinner in that moment?

I think that's a genuine moment, and it may have repercussions on the show later.

You have another episode coming later on this season, do you have a preference between either?

I can't pick. I think they're both very different episodes. I think you'll like the second one also, as I'm really happy with it. It's really creepy and eerie. I'm hoping that the general sense we get is, "Oh my God! They did that?!" I'm very happy with both. They are very different in tone, although, I think both have a connection to the mythology or their characters, at least, and in their interactions. This is a pleasure to go back into the show again, because it was such a big part of my career. It really changed my career and I'm happy and grateful to be able to do what I do.