One of the biggest stories about horror cinema in 2015 is actually the story of a trailer: When the American preview for the Austrian film Goodnight Mommy dropped in late July, it immediately went viral inspiring a rash of reaction videos and copy deeming it the “scariest trailer of all time.” (At this point, the view count on the trailer is just under 6 million.)

“We don’t want to disappoint people,” Goodnight Mommy co-director Severin Fiala told me this week in the office of Radius, which is releasing the movie on Friday. Goodnight Mommy isn’t the thrill-packed descent into hell that its fast-paced trailer suggests. Instead it’s a meditation on familial bonds about a pair of twins (played by Lukas and Elias Schwarz) who suspect the woman claiming to be their mother (whose face is bandaged because of a recent accident) is not actually their mother. Goodnight Mommy’s primary strength is its aesthetic—it’s shot gorgeously on 35 mm and is full of off-the-wall imagery (I’ve never seen anything quite like the scene in which a jar of hissing cockroaches is poured into a tank that holds a dead cat and gallons of water). It’s absolutely horrific, and only grows more so over time, but up until the devastating finale, it’s almost gentle in doling out its terror.

Earlier this week in the Radius office, I spoke with Fiala and his co-director Veronika Franz, who has co-written several of Ulrich Seidl’s movies (she’s also his wife). The conversation was much livelier than the tone of their movie might suggest—Franz in particular punctuates practically every other sentence with boisterous laughter. With me, the directors discussed auditioning 240 sets of twins, working with cockroaches, and the greater implications of violence in film. The transcript below is an edited and condensed version of our chat.

Gawker: It’s crazy the kind of impact a trailer can have. I can’t remember this level of hysterial over the preview for a relatively quiet, foreign-language film.

Veronika Franz: We wanted to ask them who cut the trailer. We don’t know. The Austrian trailer we made ourselves. I think that’s good and bad at the same time. It’s good because you’re true to the film, true to the story. But maybe it’s better if someone else takes it and makes something exciting out of it. Sometimes it’s cheating, of course. We are not sure about how far you can go.

Severin Fiala: We don’t want to disappoint people.

VF: We trust Radius. They did a great job.

The movie is thoughtful and elliptical, whereas the trailer suggests full-on horror.

VF: More action, yeah. So maybe horror geeks will be a little bit astonished. But we challenge them. (Laughs)

But also trailers are marketing. And there’s a huge history of that sleight of hand in horror marketing. There are so many terrific trailers that took basically the good two minutes of grindhouse movies and packaged them to sell them.

VF: For us it’s really interesting, because trailers are such culture here. The trailer comes out and everyone cares and writes about it. In Austria, the trailer comes out and nobody knows. There’s no reaction at all.

I don’t know if you’re aware of that showbiz cliche that says you should never work with children or animals...

SF: Yeah we are! It’s completely wrong. It sounds cool but it’s so wrong. It’s easiest and best to work with children, we felt, because children really trust you. They believe what you say. If you say, “Try to do it this or that way,” you can be sure that children will try exactly that. If it’s not good, it’s your mistake and you told them something that’s wrong. If you talk to grownup actors, it’s a lot more difficult. They’ll say, “Yes, I’ll do it exactly your way,” but of course they have their own interpretation in mind and they have prepared for the role and maybe they think the directors are idiots, so maybe they do something completely different. If it’s not good, you never know if you did something wrong or if it was the actors. It makes things a lot more complicated working with professional actors. Children, it was fantastic. They were really brave, intelligent...

VF: And the cockroaches too!

SF: They were actually stupid. The challenge was not to hurt the cockroaches. We didn’t try to hurt them, but they’re so stupid that our cockroach trainer said that if there is fire, and we have a fire scene...

VF: ...He could not guarantee that they would not crawl into the fire.

SF: So we were like, “We have to protect them.”

VF: Firewalls!

Did it gross you out to be around those giant roaches?

SF: Yeah. Actually, we didn’t like them so much...

VF: But the children did!

SF: The actress also, she was very good with the cockroaches.

VF: They had cockroaches at home for preparation. Our goal was to shoot this scene where the cockroach is crawling into her mouth without digital effects. She tried to train her cockroach to crawl into her mouth.

SF: But again, cockroaches are stupid so it didn’t happen.

That’s true devotion to a role.

SF: Well, she loves animals. So did the children. They each had one. They were called Rocky and Rambo. The only ones who didn’t like the cockroaches were us and the cinematographer. I think he could only look at them when it was filmed.

That’s a metaphor for being plagued by your own vision. You guys did that to yourselves!

VF: (Laughing) Confronted with your own worst nightmares! For us, it’s a symbol, indeed—we found out that cockroaches are actually everywhere. You know that being here in New York. Even in the best, five-star restaurants, if you know where to find them, you will find them. They are living with us together under the surface, and our film is about surfaces and what’s under them. It was the perfect symbol for us.

I read that you saw 240 sets of twins for these roles. That must have been surreal.

VF: It was the scariest part of the film! Envision...

SF: ...the waiting room with all of those twins. Really scary. But it’s fun, because with twins we had the feeling that always something happens during the audition. It’s never boring. They have something going on between each other, so even if you film it and they aren’t talented, at least they have something between them and it’s really interesting and fun to look at. For example, for the first audition we tried to play I Spy with My Little Eye. It was kind of impossible because the children always knew what the other twin was referring to.

VF: It’s the same with Rock, Paper, Scissors. We shot this, actually. It went on forever.

SF: They always choose the same!

VF: OK, five minutes...

SF: It only ends if it’s on purpose.

It’s funny to me how boisterous you guys are given the nature of your movie.

VF: (Laughs) You think we have to be more serious?

No! I’m glad you are the way you are, it’s just surprising.

VF: (Still laughing) We are very serious when it comes to work.

SF: We are very serious about the movie, but we like to play games. We wanted the atmosphere while the shooting took place to be exactly like that. We wanted everyone to have a good time because when you involve children and dark topics, you have to have a playful atmosphere [so as] not to disturb the children. And we want to have fun while shooting a film because it takes so much time. It’s a way of spending your life, and we want to spend our life having fun.

VF: That’s why we also work together as a writing/directing duo. It’s just more fun to do it together. You don’t have to take all this responsibility by yourself.

Some early reviews have placed Goodnight Mommy in the category of “extreme cinema.” I wonder what you think about explicit violence on screen versus the way that blockbusters like The Avengers: Age of Ultron portray death in a socially acceptable, PG-13 way. To me, that’s disingenuous compared to the unwavering, fixed-camera portrayal of death.

VF: It’s hypocritical, I think. I think it’s even more dangerous. You see people dying without really dying. We don’t do that. Obviously! You see the pain. We wanted to make a film we would like to see, and we want to be confronted with something in cinema and to be challenged. We really love the combination of existential themes that root in reality and with gut-wrenching cinema—cinema that gets physical so that you cannot escape from what’s going on.

SF: I think that if a movie is only entertaining or only thrilling, that’s not enough. We watch a lot of movies, and it’s boring at the end if it doesn’t really challenge you, and if it isn’t unpleasant at the same time—you want to watch it but at the same time, you don’t want to look at it. That’s something that keeps working in me as a spectator. I want the audience to be repulsed and drawn in at the same time.

VF: Society, if you look around you, is really violent. If you want to talk in cinema about things that are around you, you have to talk about violence. I think it’s good to be confronted with death in cinema. That’s what I like. Then you can think it over.

Do you have any feelings about the current state of horror cinema? I think we’re in a lull, and the response to the Goodnight Mommy trailer bespeaks an audience that is hungry for quality.

SF: What’s really sad, we feel, is that all the great masters of horror cinema that are still around don’t make new films anymore. Horror films are for debut films and, of course, many first films are not so good or made by filmmakers who still need to develop. There are lots of great directors around who used to make horror films, still could do it, but are not maybe due to financial reasons. It’s sad. Horror cinema can really talk about the world and the state it’s in. You need the right people to make the right films and the right people don’t make films nowadays.

VF: But there are some great talents around. For example, we really like Fabrice Du Welz, who did Alleluia. He’s now shooting in Hollywood. We really liked It Follows, it’s great. We were surprised by The Babadook. It kind of came up a little earlier than our film but it was actually written at the same time and it has some similarities.

Were you inspired by A Tale of Two Sisters or The Other? There are a lot of thematic similarties...

SF: We haven’t seen The Other.

Really?

VF: Some friend of ours said, “You have to watch this,” and we never did.

SF: We were inspired maybe more by The Innocents by Jack Clayton or maybe Bunny Lake Is Missing by Otto Preminger or Eyes Without a Face by Georges Franju or all the rip-offs of Eyes Without a Face by Jess Franco.

You’ve been working on movies forever with your husband, Veronika. And now, about 15 years later, you’ve directed your first narrative feature. Were you always waiting to do that?

VF: No, no, no. Not at all. I’m not that way. I’m not a strategical planner. I’m kind of driven by my own curiosity to explore the world and to develop further as a human being. [Severin and I] made a documentary together before about an Austrian filmmaker [Kern, about Peter Kern]. We had the feeling someone had to do a film about him and nobody wanted to because he’s a real mean guy. (Laughs) But still we said, “But somebody has to!” So we did that. It was a really challenging experience. We started to work together on the documentary, and while we edited it, we had this idea for Goodnight Mommy, and we started writing. One came to the other. After we wrote the script, we said, “OK, we made the documentary, we wrote the script together, let’s direct it together.” If you had asked me 10 years ago, “Come on, direct a film,” I would have said, “Are you crazy? I’m not going to direct any film.”