Some horror films are not easy to watch. But for many scary movie fans, that's exactly what we're looking for—something so new and shocking or gut-wrenching that it leaves us shellshocked or grabbing onto our fellow audience members in fear.

I'd definitely put writer/director Demián Rugna in that category. His brutal new film, a story of contagious possession called When Evil Lurks, just premiered in the Toronto International Film Festival's Midnight Madness block, and fans of the grotesque have certainly been enjoying the film. It's one that left me reeling for days, and as you'll read below, contains imagery and practical effects I've never seen done before, especially this well.

IFC Films is releasing the film in theaters on Oct. 6 and will stream it on Shudder a few weeks later on Oct. 27.

We spoke to Rugna ahead of the film's wide release via Zoom. Please note there are mild spoilers for When Evil Lurks in our conversation, so consider going to see the movie before coming back to learn from Rugna.

Enjoy! And let us know how you sleep after you see this one.

When Evil Lurks – Teaser Trailer | HD | IFC Films ft. Ezequiel Rodríguez, Demián Salomó

Editor's note: This conversation has been edited for length and clarity.

No Film School: I have been a fan of your work for quite a while. I love Terrified. I've recommended that movie to so many people. With [When Evil Lurks] coming out, I'm going to do the same thing with a lot of my diehard horror friends.

Demián Rugna: Thank you. Thank you. Yeah, it's cool. It's a horror movie. I mean, a horror movie. When you see a horror movie, you are expecting to feel something.

Probably, I exceed the limits, but you are still watching a horror movie, so for me, there are no limits. If I can, if producers and the system allow me, I take advantage [of] that.

NFS: When I finished watching this, my husband came home and I was like, "I have seen things in this horror movie that I have never seen before." What inspired the film?

Rugna: Yeah. Well, I don't know really, but I guess one of the things [that] inspired me is I live in Argentina. In Argentina, you have a very big land with [a] plantation. The pesticides are killing people. I mean, the disease in the people because of the pesticide is normal, and the workers who live inside those fields are dying of cancer. Little children are with cancer, and nobody knows or nobody cares because the owners of those lands are powerful people. They must continue working because they need it, and they must continue living there because they need it.

I guess the idea of disease in the middle of nothing with people that [don't] care, I guess is one of the first inspirations for the Rotten Body.

Another obvious [inspiration] is my decision to move away from the city to live in a rural town. Obviously, it gave me the inspiration of being in a rural town or countryside is because I moved far away from [the] city.

Ezequiel Rodr\u00edguez and Demi\u00e1n Salom\u00f3n in Demi\u00e1n Rugna\u2019s 'When Evil Lurks'Ezequiel Rodríguez and Demián Salomón in Demián Rugna’s 'When Evil Lurks'Courtesy of Shudder and IFC Films

NFS: As I mentioned, there are things in this film that I just feel like I've never seen in horror before. Things like the dog attack. I'm interested in how you come up with those really shocking moments.

Rugna: Well, in relation [to] the dog attack, I always have the idea of a dog kidnapping a little baby. For me, it was an idea that had been roaming in my head for a couple of years.

When I moved to the countryside, I had my neighbor as a breeder, a guy who sells this kind of dog. And that kind of dog gave me the idea of this big mouth that it has, it fits [the] head of a little baby.

When I put it in the movie, I thought, "How [do] I tell this thing? How [do] I show this thing?" I decided to be explicit because I needed this kind of violence to define all the situations that [are] going, growing during the script. Because all the time, you just see the broken body, and there's something that could happen, and all are afraid of that.

The idea is [the characters] are telling us something really, really bad could happen, but the audience does not realize what kind of level of madness is going to happen. So I decided to put [it] in front of you. ... They're really, really scared because [of] this, and this is the act in front of the camera, killing one of the characters. And then showing the shot with the ax, the woman in front of you, because this going to happen if the evil spreads.

Even with the dog, I choose to showcase. I won't hide anything here—well, if I can show everything. I couldn't show everything because I don't have enough money to show everything, but in front of you, things can happen.

The decision was that, OK, I need to really, really show in front of the audience why they are too scared, and then hoping to scare the audience, and put the audience in the position that I'm betting to all the time asking, "Please, I don't want to see something again,in the movie." That's what the idea [was] to be violent in that moment.

Demian Rugna\u2019s 'When Evil Lurks'Demian Rugna’s 'When Evil Lurks'Courtesy of Shudder and IFC Films

NFS: So you mentioned budgetary restrictions, but I feel like the movie doesn't suffer for it. I mean, that violence is very visceral. Can you talk about your effects and the practical tools that you used?

Rugna: Yeah. Well, there's no CGI in the movie. There's nothing recreated by a computer. Yes, there's a lot of VFX. That was part of the practical effects. I mean, I used to build movies with 85% of practical effects and 15%, 20% of the effect that supports the practical [effects].

[On] one hand, [it's] because I don't trust 100% in the CGI. Because there was a moment when we thought we could make a dog with CGI, we could make a goat with CGI. But finally, we decided no, because it's too expensive. ... I'm not sure it's going to be real and too risky for a small movie ... I don't know if [it's] the correct path, but I'm used to working with practical effects.

For the dog scene, we trained the dog. It was too hard because the dog is a breed that is almost impossible to train because it's too lazy, too stupid. It's not the correct breed. Obviously, the trainer shared [with] me another option—Rottweiler, Malinois, another kind of dog—but you're used to [seeing] that dog in old movies, that breed. But I wanted to have another, this horrible dog. ... And obviously, then the effects, all the time, are the stars in my movies.

I mean, the stars, the celebrities in my movies are the effects. When the effects come to the set, they are celebrities.

Most importantly, in the work, is it works. If it doesn't work, my movie goes to hell.

NFS: It does work. It looks amazing.

Rugna: Thank you.

Ezequiel Rodr\u00edguez in Demian Rugna\u2019s 'When Evil Lurks'Ezequiel Rodríguez in Demian Rugna’s 'When Evil Lurks'Courtesy of Shudder and IFC Films

NFS: Since you've now made several very well-received and strong horror projects, I would love it if you could give some advice to filmmakers just starting out, on how to make a good horror movie.

Rugna: To make a real horror movie is just trying to not copy [other] movies. Try to [borrow] from [other] movies, but do not copy. I guess all the filmmakers that I met made horror movies using a path similar to other movies that they are in [vogue].

I mean in fashion. When the fashion of possession movies is now, you're writing, you are working with this kind of element, but probably, you want to make a movie in three or four years. You want to make a movie [but] there is no more ... fashion for this kind of movie.

Do you know what I mean? It's trying to be fresh, trying to be yourself and make something not too different. But inside a genre, try to give something new, something that you really like enough because it works. Zombies. You make a horror movie with zombies because when you get that movie, the zombies are no more in vogue.

Try to push a lot, yourself. Because this is a long life, a long-time career, you have a lot of time to get the results. Probably the results of your first movie won't be what you are expecting. It happens, but you must continue doing it.

The secret of my career is all the time working in my process, writing, and feeling better, also. Write more than watch movies. This is hard to say, but I prefer to create than [watch] because the time that you spend creating is a [blank] check. I mean, it gives you a lot. It gives you a lot. Create all the time.

Anyway, the problem with the filmmakers, they are going to make a first movie, they're trying to be Orson Wells in his first movie. No, you need to work. You need to make it. You need to fail. The fail is the first step of your career.