You know how Jaws made you never want to swim in an ocean again? Or how Psycho turned showers into potential death traps? Well, when It Follows opens in theaters early next year, it's going to popularize abstinence. Seriously, this movie could close more legs and soften more hard-ons than a Donald Sterling sex tape.

Another thing It Follows has in common with horror classics like Jaws and Psycho is that's really f'n scary. Like, the most endlessly unnerving joke-free American horror movie since 2002's The Ring remake.

Written and directed by thirty-something Michigan native David Robert Mitchell (The Myth of the American Sleepover), It Follows comes with a concept so simple and genius that it's hard to believe nobody's thought of it before. After Jay (aces newcomer Maika Monroe) has sex for the first time with her new boyfriend, Hugh (Jake Weary), he tells her that he's just passed something onto her. No, it's not an STD—he's just given a sexually transmitted ghost/monster, one that takes the form of various people only the inflicted person can see, and only he or she can see those people. You're dead if the creature catches up to you. The only way to save yourself is to have sex with someone else and pass the nightmare onto them.

Mitchell takes full advantage of that inherently brilliant premise. Once the slow-footed threat is introduced, It Follows becomes an incredibly unsettling exercise in horror. Your eyes are constantly scanning all sides of the camera's frame, looking for someone approaching Jay and her friends from behind. Watching It Follows is basically you sitting in your seat riddled with anxiety for 97 terror-filled minutes, while the original score from popular video game music composer Rich "Disasterpeace" Vreeland pummels your senses with its '80s-John-Carpenter-soundtrack-on-PCP energy.

This is the new great indie American horror film we've all been waiting for. After its triumphant world premiere at the Cannes Film Festival in May, It Follows is screening here at the Toronto International Film Festival before its official theatrical release in early 2015. But now's a great time to start getting excited. And to provide a deeper context as to why you should be excited, Complex sat down with David Robert Mitchell in Toronto to discuss the mechanisms of what's shaping up to be horror's next big thing.

I've read that the idea behind It Follows stems from an old recurring nightmare of yours. What happened in those nightmares exactly?
I kept having this same recurring nightmare that really scared the hell out of me. In those nightmares, I was being followed by something that would look like different people at different times, and the scariest thing about it was that nobody else could see it. When I was a kid, I just knew that it was a monster, and that I could try to run away but it would keep coming towards me, no matter what I did. But it would always walk very slowly towards me, even if I started running away. In the dreams I could always get away from it, but it was this feeling that this thing was constantly watching me and constantly following me, even when I couldn't see it.

When did you take nightmare concept and turn it into what's now It Follows? Has this been a movie idea you've developed in your mind since you were a kid?
It took a really long time. I had those nightmares as a kid, when I was, maybe, 10 or 11 years old or so. As I got older, I would always remember it, and in my late-teens, I thought, "It might be interesting to take that idea and try to use it to make some kind of a horror film." I've always wanted to make movies since I was young. But I didn't have it all figure it out—I just knew I wanted to turn it into a movie at some point.

So I kept thinking about it. Over the past ten years or so, I've just kept thinking more about it and connected it to the idea of passing this "thing" onto other people through sex. It just seemed like the perfect way to connect people physically and make the "thing" something really intimate and, to some degree, inevitable.

The movie has a strong old-school vibe. Does that sexual element have any connection to how the old slasher films and horror flicks of the '80s used sex as a deterrent? 
Well, somewhat, but to me it's a little more complicated than that. How I see it, and how I tried to convey it in It Follows, sex is the way the haunting starts but it's also the way to survive as well. So it's not as simple as using sex to honor or reference those older horror films, which, don't get me wrong, I grew up watching and love. In my film, sex is the only way you could survive, and that felt like something new. I've never seen that before in a horror film.

Whenever the characters are watching TV, there's always an old black-and-white B-movie playing. That makes it pretty clear that you were working with heavy nostalgia.
It's true, so much of It Follows comes from classic horror. It was about trying to seamlessly mesh what's so great about those older horror films into something that feels contemporary but, at the same time, doesn't seem to exist in a specific time or place. I like the idea of mixing eras and having the film exist slightly outside of time. There's a feeling that It Follows could be happening in the 1980s, but there are a few things that are modern in it. And some of the thing the kids are watching don't really make sense—the last thing you'd expect these kids to watch is a monster movie from the 1950s. It's a little outside of reality and dreamlike.

Another thing about It Follows that brings to mind old-school horror is how the monster always walks very slowly towards Maika Monroe's character. It's similar to how Michael Myers and Jason Voorhees always stalk their victims. As a kid, I'd watch the Halloween and Friday the 13th movies and think it's weird that they'd never run after their victims, but, at the same time, their walking scared the shit out of me.
[Laughs.] The same with me.

Did you go back to those movies to see how directors like John Carpenter made the walking monster work so well?
Yeah, definitely. Before making this film, I went back and watched a ton of my favorite horror movies. There was a bunch of John Carpenter stuff, for sure, like Halloween and The Fog. I went back to some old David Cronenberg, some Roman Polanski, some Ingmar Bergman. I also watched Creature from the Black Lagoon again, and Nosferatu.

But as far as the walking thing, I just really tried to have faith that if we set it up correctly, the idea of the walking would work. For me, it wasn't built off of saying, "Oh, they did the slow-movement thing in Halloween, so I should do that here." It was really connected this thing in my head of, "That's what happened in my nightmare from when I was young." I still remember some of those images. One of them is, I was with my friends during recess in the school parking lot, and I saw this kid on the other side of the lot walking towards me really slowly; I pointed him out to my friends but they didn't know who or what I was talking about, and I just knew it was this monster coming to kill me. Those are the kinds of images I tried to put into the movie.

Maybe the walking thing is scary for people because it's a subconscious thing—I really can't explain why it works. I just felt like it could in my movie. But, yeah, there were moments where someone would say to me, "Wait, so it's just people walking towards this person? Is that really going to be scary?"

I'd imagine it didn't look very scary on the set while you were shooting those scenes.
[Laughs.] No, it didn't, and that's the challenge. That's why I think horror is so difficult. Admittedly, it was a little tough. I had never made a horror film before. I just love them as a movie fan, and I just put everything I had into being able to do one. On the set, though, it's hard. You have to constantly remind yourself about the accumulated tone and anxiety that the audience will have once the movie is all put together. The images of people walking are only scary when they're seen within the movie's full context, you know? They're part of the overall mood and sense of dread I tried spreading throughout the whole movie. You don't have that in the moment, on the set, but you have to understand that the audience will have that when they're watching it.

I felt that at the script stage and I really tried to design the camera movements and the scenes in a way that would, hopefully, make the image of people walking towards you scary. After that, all I could do was have faith that it would work for the audience. That's what so hard about horror—having enough faith in your vision to feel that it'll scare people once it's all pieced together.

It's so effective because of the way you use wide-angle shots and 360-degree pans to show all of what's behind and around the characters. It causes the viewer's eyes to really do so much of the work. What was your approach to using the camera movements to enhance the film's scariness like that?
It was simply that. I wanted to shoot pretty wide-angled lenses, and I wanted to make sure that we could see far into the distance. I wanted there to be a fairly open frame. It was something designed at the script stage; we built it into the shot designs. You would have some extras way off in the distance, and sometimes it would people connected to the "it" and sometimes not. And once we set up that this happens and can happen, then you sort of hand it off to the audience and put it on their shoulders to feel the need to look everywhere at all times.

The film's designed to say, "We're not going to tell you every time that something dangerous is in the frame or is approaching," and once you know that, you will start to look. And once you do start looking, you know that this can happen at any point, and there are some long gaps where you're waiting and wondering. You'll then do that the whole time, and the dread builds from that. That was the hope, at least.

You set that up well, too, with that shot in the beginning where Jay's floating in her pool and the two neighbor kids are watching her by sticking their heads over the fence, and she says, "I see you." You feel like Jay's being watched already, before the monster starts following her.
Yes, exactly. A lot of the film is subjective—there are subjective moments with Jay, but there's also a feeling of unease, as though the characters in the film are always being watched.

There's been a ton of praise for the film's score and sound design. Critics have been comparing it to the synth-heavy, electronic stuff John Carpenter used to compose and to what Goblin did for movies like Dawn of the Dead and Suspiria. What was your thought process behind giving It Follows that kind of vintage sound?
I always knew that I wanted an electronic score for this. I found Rich [Vreeland], who goes by Disasterpeace, while playing a video game called Fez—it's a really great game. It has this amazing soundtrack. I loved the music so much that I looked him up online and contacted him and said, "I'm gonna make this horror film and I'd love to have music like what you made for Fez in it." I sent the film to him and he was interested in working on it. He's super talented and has a big following for doing music for video games, but he'd never done a movie score before.

When we started talking, I said that I wanted something that could be beautiful and melodic in some places and then also an assault. The score borders on being assaultive noises in some places. To be honest, the score came together in about three weeks, which is a really fast turnaround. From the point at which the film was accepted into Cannes, Rich worked day and night nonstop to put it all together. It was a real whirlwind.

Before he started making the original music, though, we put some temp music into the film to help him get the mood down. For that, we used a lot of Rich's stuff, actually, and we used a bunch of John Carpenter's scores.

Did you temp with any Goblin?
You know, we didn't temp with any Goblin. I really like their stuff but it didn't work for this film, at least not to me.

That's surprising, some of the It Follows score totally reminded me of Goblin's work on Suspiria.
Oh, for sure. I can see that. That's coincidental, though. We built a pretty elaborate temp score because it was necessary to get to that stage where everything worked. Music is so important in this movie.

It's interesting to hear you describe the music as "assaultive," because there are moments in It Follows when the score gets really loud and really chaotic. Did you ever stop and say, "Is this music almost too assaultive?"
We talked about that, yeah. It's a fine line to walk, but like a lot of the decisions we made for this movie, it came down to me just saying, "Let's go for it!" Since I'd never made a horror movie before this, everything about making It Follows came down to me trusting my gut and taking chances. It's a horror film made by a guy who's always loved horror films. I knew I had a really cool and original idea, so I put a lot of faith in that. That gave me the confidence to really go for it in every way possible.

For more of Complex Pop Culture’s coverage of the 2014 Toronto International Film Festival, click here.