[This story contains spoilers from the sixth episode of FX's American Horror Story: Apocalypse, "Return to Murder House."]

The secret is out about Michael Langdon.

Fulfilling a prophecy made to viewers seven years ago in season one, American Horror Story finally and officially identified the satanic baby from Murder House as the Antichrist. The revelation came in the highly anticipated crossover episode during week six of season eight, AHS: Apocalypse. Perhaps even more fitting, the extended 78-minute episode, titled "Return to Murder House," was directed by the actress who made that prophecy back in 2011.

"Their worst fears have been confirmed. Once you have that information, everything changes," Sarah Paulson tells The Hollywood Reporter of Michael's destiny being revealed and how it will define what everyone on Apocalypse does next.

Back in season one, Paulson played a medium named Billie Dean Howard. When Michael was born, Billie Dean predicted that he would bring about the end of the world. During Wednesday's episode, Michael's biological mother, Vivien Harmon (Connie Britton), confirmed that Michael was "born of the evil from" Murder House, a home built over the portal to hell. "The source of darkness is his true father and he is here to destroy the world," she said.

Paulson reprised Billie Dean during the episode and was joined by a handful of beloved AHS characters also making their long-awaited returns, including Constance Langdon (Jessica Lange), the entire Harmon family (Connie Britton, Dylan McDermott and Taissa Farmiga), Tate Langdon (Evan Peters) and Moira O'Hara (Frances Conroy).

Below, Paulson takes THR behind the scenes of her directorial debut to share what it was like to direct the key AHS episode (and former series star Lange), tease what comes next and muse about whether this was co-creator Ryan Murphy's plan all along.

This has to be the most exciting episode of AHS to direct. What was your conversation like with Ryan Murphy about making your debut behind the camera with this crossover event?

I was always set to direct an episode this year but my episode was supposed to be episode eight, which hadn't been written yet and was going to shoot about a month later than episode six. A bunch of times, I had tried to get out of it because I was so scared. I was driving down Santa Monica Boulevard when he called me and said, "I want you to direct episode six instead." I said, "What? That's like, in a week." And he said, "It's just the one you have to do. You'll get to direct Jessica. It's going to be the episode everyone is waiting for. It's just the one you should do and you're going to do it." And he did the thing he always does where he says, "This is what you're doing," and I just say, "Yes."

When you then realized it was the Murder House crossover — and that you would be directing a handful of highly anticipated returning castmembers — how did you react?

It was a tiny bit intimidating — just the idea of doing it all was scary — but the idea that I was going to be doing this with people who are my friends; I was going to have to come at this from a different place. Not as an actor, but as a director. And having never done it before, I wasn't quite sure what that was going to look like — or whether or not they would go along with it. You just never know what's going to happen and so it was an interesting thing. What was I going to do when I had to approach Jessica with a note or an adjustment of how I thought a scene should be played? She's the actor I've worked with more than any other actor in my life — which is an incredible thing to say when you're speaking about Jessica Lange — but it's always been actor to actor, where we figure things out together. This was a different situation. I was in charge, in a way. And the same thing with Kathy [Bates] and Franny Conroy and Emma [Roberts] and Billy [Porter], and everyone who was in my episode.

You also appear in the episode as Billie Dean Howard, one of the three characters you play this season. What was it like the first day, and how did you learn to balance wearing all those different hats?

My first day was like the first day of school. I feel it every time I walk on a set as an actor for the first time. I always feel like this is the time someone is going to say, "We didn't mean to give you this job, actually." I felt that even more walking into shoes I've never worn before. It was totally nerve-wracking and using an entirely different part of my brain. As an actor, I try to engage more of my emotional life and in this instance, my emotional life would sometimes be a hindrance. It's a director's job to be positive and to be a fearless leader at all times. There were times where I was getting so panicked about how I was going to pull something off in the time allotted that I had to remind myself to not get so hysterical, as I tend to do when I'm doing a scene as an actor and I'm not feeling that it's going my way; I get frustrated with myself and I had to try to work on being a little bit more gentle. It was a very confronting experience. I had to come up against a lot of things about myself that are not the greatest qualities!

Was the episode always intended to be extended or did you make changes once you began filming?

Let's put it this way: The episode I shot right before, where I was just acting, I think it had 28 scenes, or 28 strips as they are called on a schedule. Mine had 72. It was more than any episode than I think we've ever done, so there was no way it could be the traditional length of an American Horror Story. There have been past seasons, I think, where we've had episodes around this long. But there was no way that an episode that had 72 pieces to it was ever going to be a 42-minute episode, ever. It was also that feeling of people wanting to be reunited with these characters, so let's not give them short shrift. Let's give them more time with these characters and let the audience have their time with these people for the last time.

How did it feel to be back on the Murder House set, where your AHS journey began?

I had worked with Ryan [Murphy] on Nip/Tuck before Horror Story, but the beginning of my Horror Story life absolutely began in season one. And I was reprising the character I played in season one while directing myself, as well as directing Jessica and Taissa [Farmiga] and Evan [Peters] playing all these beloved characters. It was really wild. In that one scene where Billie Dean enters, there's a lot that happens right before I walk in. I was standing off camera with my nails on and my wig on, listening to Emma and Billy do their portion of the scene before I entered. Then I had to drop my headphones, that you listen to when you're directing, on the ground as quietly as possible and enter the scene. It was really hard to split my focus. I was paying attention to all the things in the scene that I was wanting to adjust in the next take, and then I had to go in there and act as well. I don't think I will do that to myself ever again, direct and act. One is enough! (Laughs.)

This episode nicely wrapped up the stories for all the favorite Murder House players. What were your conversations like with Jessica Lange during her scenes, and how easily did she slip back into being Constance?

She slipped back very easily into Constance. It's a character I think she has a particular affinity for. I can't speak for her, but she was incredibly receptive and you could tell she was just wanting to give me what I wanted. She was very generous and indulged me in doing multiple takes and really was there for me. It was really extraordinary. So was Kathy, Emma, Billy and Franny. Everyone. I really felt like I was doing this with my family.

What were the biggest risks that you felt you took with the episode?

There were some choices I made to not shoot peoples' faces. In Constance's section of the story, she spends a lot of time walking into rooms and responding to the horrible things Michael has done. I wanted her to not have to do the same beat of surprise every time. There was one moment where she discovers something and I never shot her face, it was all done in her back and profile. I remember turning to Jessica on her last night of shooting and she said, "What are you thinking about the next scene?" And I said, "Well, if I were really brave, I don't think I would shoot your face." And she said, "Oh, please be really brave." I had her permission to do that and so I didn't shoot her face; and it was great that I didn't. There are only so many ways you can walk into a room and be surprised about the same thing over and over again.

Also, it wasn't necessarily brave, but I made some strong choices in using slow motion a couple of times and I had people look down the barrel, which was a common thing that happened during season one where people looked into the camera. That was something I knew I wanted to do. I did other versions, but in the final cut, we used the ones where they do. I felt very strongly about that. Also, the shot of Moira and her mother walking off into the night together and letting that play. It's our last time seeing Moira and she's at peace now. I visually wanted to communicate that without doing something as traditional as close-ups on their face.

The feel and tone certainly invokes season one and, on top of that, AHS show mythology explodes in this episode. What were some of your conversations with Ryan Murphy like about the magnitude of this episode?

The thing that was so extraordinary about it is that he really trusted me. And it was really all on the page. I do feel I really understand the world, at the very least. Things like when Violet and Tate finally reunited, it was really clear to me what we had talked about. I know what I would want as a fan of the show and what I would want to see, and so I tried to think of it from that perspective, too.

When Ryan explained his idea for this crossover season, did you get a sense of how much had long been in the works or plotted from the start?

As beautifully as we are able to execute the interwoven realities of the seasons, I think some of it is incredibly planned and thought out, and some it is the beautiful alchemy that unfolds in that writers room. Where they are saying, "Oh my God, we can do this and this," and one thing leads to another. Back when season one was happening, I have to say, I don't think he had this endgame in mind — as brilliant as Ryan is.

How does this visit back to Murder House send the rest of the season on a new course?

By the end of the episode, it's all there. This is the episode where the warlocks and the witches learn that Michael is the Antichrist and that their worst fears have been confirmed. Once you have that information, everything changes. You can't un-know it. The witches and warlocks now know what they're dealing with and how terrifying that new reality is. I think it sends everyone into an appropriate panic state. And how they handle it will remain to be seen.

Is there really any other way for this season to end aside from the witches saving the world?

Well, I hope so. But we're still shooting the finale so I can't give that away just yet.