Warning: This post contains spoilers for the “Plus One” episode of The X-Files.

Phew — is it hot in here or is it just us? This week’s Chris Carter-penned X-Files installment, “Plus One,” was one of the steamiest in the show’s history … even though Fox Mulder and Dana Scully (David Duchovny and Gillian Anderson) didn’t do anything more on camera than cuddle. In the midst of an investigation into a strange case of murderous doppelgängers, the paranormal investigators provide an overdue update on their complicated romantic status by sharing an intimate night together in their hotel room. Initially occupying separate beds, an emotionally troubled Scully approaches Mulder with a request: “Can you hold me?”

Once in bed, the duo — who, let’s not forget, have a child together (or do they?) — engage in some sweetly emotional pillow talk about taking care of each other in their old age and the unlikely chances of spawning another rugrat. As Scully turns to face Mulder with a smile on her face, the camera pans subtly away to the left. When we cut back to the room later on, there’s obvious evidence that they’ve gotten hot and heavy beneath the sheets, from his rumpled tank top to her bare shoulders. It’s quite possibly the closest that The X-Files has gotten to a sex scene in 11 seasons — or, at least, close enough to make us want to rechristen the series The Sexy Files.

“The Sexy Files! That’s pretty funny,” says the hour’s director, Kevin Hooks, with a good-natured chuckle. A former child actor turned veteran director — his past episodic credits include everything from St. Elsewhere and China Beach to Prison Break and Lost — Hooks says he was excited to learn that his first X-Files episode would be such a momentous one for the main characters. “That scene is obviously huge, and when I read the script I was really excited about it. It’s something that X-Files fans have been looking forward to for some time.”

Hooks filled us in on how he brought the sexy back to The X-Files and how he accomplished the difficult task of making a simple game of hangman seem like the scariest thing ever.

Yahoo Entertainment: David and Gillian obviously have a long history together that they drew on for the more intimate moments in this episode. How did you see your role as the first-time director coming into that relationship?
Kevin Hooks: The biggest challenge in doing a show that has the long history that The X-Files has is to gain the trust of the cast as well as the crew. That’s something that I really tried to invest a lot of thought and energy into, knowing we were going to get to a place of intimacy that hadn’t been explored on the show in a while. Because David and Gillian are so close and so invested in these characters, they brought a lot to it that I couldn’t even have anticipated. They did a lot of work with Chris in terms of how to handle the passage of time and the ages of the characters. I just wanted to impress upon them the trust that I felt in them and that hopefully it would be reciprocated, which I think it was. I wanted to say my piece and get out of the way, because what they brought was going to be rich, and I wanted to make sure they felt comfortable enough to offer that.

The pillow talk sequence is the centerpiece of the episode, and you allow it to unfold in a very relaxed, almost languid way. It’s increasingly rare to see that kind of pacing on network television. How long did the scene take to shoot?
We shot most of the hotel material in one or two days. What was paramount for me was to make sure that the scene played as honestly and earnestly as it possibly could. I didn’t want to rush the actors through takes; it was important to let that scene breathe, and I felt it worked well. In an episode that really does have a [fast] pace to it, that scene needed to breathe to be authentic.

As intimate as it is, we never do see Mulder and Scully kiss. Were there versions of the scene where things got more physical?
Everybody was in agreement that we didn’t want to sell any body language that would indicate where it was going. The reveal was in the time cut when Mulder gets up to go to the bathroom, and you see bare shoulders. That’s when you realize that something has changed — that they’ve probably gone to another level, to use a euphemism. [Laughs] So we took great care with the body language to ensure that we didn’t ruin that reveal for the audience.

It’s not unlike the way Hollywood films functioned during the Production Code days — you had to hint at things rather than be explicit.
Well, that’s the irony of the structure of that sequence, because we were restricted from what we could show for different reasons. We did it to serve the story as opposed to being dictated to by Standards and Practices.

Some lines in that sequence — like Mulder’s comment about Scully having plenty of “scoot in her boot” — sound improvised. Did the actors have leeway to play around that way?
As much as Chris wanted to make sure that we got the scripted dialogue, he also trusts David and Gillian to try different things. I don’t remember if “scoot in your boot” was scripted or if it was David, but there’s some improv in there that works really well. When you’ve lived with characters for as long as they have, it becomes instinctive and just adds to the spontaneity of it all.

Let’s talk about the other major hurdle you faced in the episode: making a game of hangman seem frightening, not goofy. How did you approach those particular scenes visually?
[Laughs] I knew there were going to be a ton of inserts, but I wanted to make sure that we didn’t rely entirely on them. I always think that camera movement creates drama, so I tried to get some push-ins and camera movements around that material. We also talked a little bit about jump-cutting in the editing patterns. Karin Konoval plays multiple characters in the episode, and one thing we talked a lot about was what grade of lead we’d use in the pencils. I wanted to feel the texture of what was being written on those pages, and Karin decided that she was going to make one of her characters left-handed and the other one right-handed. It was a wonderful idea that worked well with what the whole hangman game was supposed to be in the episode.

I’ve always liked the conceit of doppelgängers as boogeymen. Did you enjoy playing around with that notion behind the camera?
Chris and I talked a lot about designing shots that put characters in the same frame, whether it’s the young man in the car in the beginning of the episode or the fight Mulder has with his doppelgänger. We really wanted to give the audience visuals that felt a little bit more original and a little bit more fun than some of the other stuff where he had to rely on cuts. Putting both characters in the same frame was a wonderful exercise in the doppelgänger of it all.

The last shot of the episode — where Scully opens the adjoining door to their hotel rooms and finds Mulder waiting — is very playfully intimate as well. You can imagine where the scene goes next, even though we don’t see it.
It’s very true. This sort of goes to what I was saying about relationships that exist well beyond a director coming in to do one episode in Season 11. There’s a foundation there that they’ve been working from and building on for years, and I just wanted to help bring it out. It was a lot of fun; watching them work together was amazing.

Were you a Mulder and Scully ‘shipper back in the day during the show’s original run?
Working as a director and producer in television, you don’t get a chance to watch a lot of the shows being done. And that was before binge-watching! So I can’t say that I was avid a fan as many, but I certainly followed the show and aspired to be part of it. When I first talked to Chris Carter about doing [this episode], I told him that wherever I worked previously in the business, it was almost like “Six Degrees of X-Files.” I always met someone who had worked on the show, and thought they had worked with me on it! [Laughs] Finally, I was able to actually do the show and share the mystique of The X-Files.