There’s a lot that’s creepy in director Yorgos Lanthimos’s new film, The Killing of a Sacred Deer, which premiered at Cannes film festival earlier this year and which is out in New York and Los Angeles Friday. To start, there’s the opening frame: a still-beating, fleshy heart, laid on an operating table, held open with clamps. Then, there’s the very premise: A family of four—a surgeon father (Colin Farrell) and ophthalmologist mother (Nicole Kidman) and their two children—begins, one by one, to succumb to an undiagnosable illness. First, paralysis; then they’re unable to eat, seemingly out of revulsion for food; and then, not long after, they start to bleed from their eyes. Finally, they die. (This isn’t even a spoiler, so early are the terms of Sacred Deer’s social contract laid out for the audience.) There’s also the creepily affectless tone, a Lanthimos trademark, with which the actors deliver their lines, and the discordant, clattering score. And looming over it all, there’s Martin, the endlessly creepy teen played by Irish actor Barry Keoghan, who was last seen as the sweet, unassuming (and ill-fated) surrogate son of Mark Rylance in Christopher Nolan’s war epic Dunkirk.

There’s something a little bit off about Martin. The high-schooler has seemingly cultivated a friendship with Steven, Farrell’s surgeon character, who gives his young charge expensive watches and invites him over for family dinner. But Martin, with his flat stare and penchant for lurking in the hospital car park, not to mention his efforts to set up Steven with his own widowed mother (Alicia Silverstone), is unnerving, and Steven begins to distance himself. Here, Martin turns downright evil. His father, he reveals, died on Steven’s operating table—guilt over which still haunts the surgeon, who was struggling with alcoholism at the time. Martin is responsible for the paralysis gradually besetting the family; Steven can halt its progress if he simply picks one member of his family to die before they reach the critical eye-bleeding stage. (The title is a reference to a myth in which the Greek king Agamemnon kills a stag, the sacred animal of the goddess Artemis; Artemis retaliates by forcing Agamemnon to choose between losing a war and sacrificing his own daughter.)

In one memorably deranged scene, Anna, played by Kidman, confronts Martin, pleading with him to spare the family. He sits in front of her, in his boxers, shoveling massive forkfuls of cold spaghetti into his mouth as he explains to her, with chilling equanimity, the choice Steven must make. In another, Martin bites into Steven’s arm; when Steven pulls free, Martin sets his teeth on his own arm, biting out a chunk and saying through bloodied teeth, “It’s a metaphor.” (Just as The Lobster’s billing as a black comedy didn’t quite cover it, horror isn’t sufficient to characterize The Killing of a Sacred Deer, which is its own kind of dark comedy.)

At Cannes, The Killing of a Sacred Deer elicited boos from the audience (putting it in the illustrious company of such films as Pulp Fiction, Marie Antoinette, Taxi Driver, and Okja); in reviews just ahead of its wide release, it earned both rapturous praise and skeptical criticism. Two days after his 25th birthday and just a day before its wide release, we caught up over the phone to discuss his role in the film. He was in Los Angeles to promote the film, and when we spoke, he was in the middle of trying to fix the light meter on the camera Lanthimos gifted him after they wrapped production. (Photography is just one of his many extracurriculars, including boxing, which has got Kidman concerned.) He weighed in on the polarized responses to the film, the entirely strange audition process alongside his co-star Raffey Cassidy, and, of course, eating bowl after bowl of pasta in his skivvies with Nicole Kidman for company.

How did you get this part?

It was the audition process and stuff like that, and then we had to go to London to meet Yorgos. We done some weird audition process and stuff, and I liked it—I liked the games we done in the audition process. It was all part of distracting us from attaching emotion to our words.

What kind of games? What was weird about it?

Me and Raffey were playing with tennis balls and keeping one hand in the air while we talked and beating our chest like that [beats his chest] and stuff. Just distracting things to keep our mind off attaching emotion.

All the characters in Yorgos’s films have this very flat way of delivering all their lines. What kind of instruction did he give you on that and how you made it work for the character?

He didn’t really, that’s the thing. He never really talked about doing it in a deadpan or a monotone kind of way. He never said that. It was always just, you kind of do it that way going into a Yorgos world. You take that from his previous work: He has these rhythms and this language and this certain way of acting, so he never actually directed us to do it that way. The direction was pretty simple—it was like, stop moving your head and keep your head straight and say your line a bit faster. It was pretty simple and precise.

Were there any moments where you had to kind of break through that flatness?

You tend to, as an actor, attach emotion to some words. You always come in with a feeling that you’re seeing or something. But with this, it was very refreshing—you just go in and say your lines.

You were familiar with Yorgos’s work before this, right?

Oh, yeah, yeah. I was familiar with The Lobster and stuff.

What made you want to play this part?

A Yorgos Lanthimos movie is a unique movie. It’s a unique world, and [he has] his own rhythms and languages. It’s experimental, in a way, and it’s refreshing, as an actor. I wanted to try something like that. It’s like stage—I want to try stage some time. It’s got the same things, the camera and technical things, blocking, whatever, but the acting style and the directing style is so different to anything else I’ve done.

Martin is sort of the malicious force in this movie, but there’s also something very needy about him; he’s looking for Steven to fill the father-figure role for him. So I’m wondering how you balanced those competing concerns of being a child in search of a parent but also being the physical embodiment of the revenge plot in this movie?

[Laughs.] Um, I mean, these are things I didn’t think of. I didn’t. I just played him as what’s on the paper. I had no attachment to this lad. I had no backstory. If you meet me in person, I’m pretty as far opposite as Martin as there is, and it’s nice, as well, that I could go there, but that was all in the writing and Yorgos’s construction. There’s a lot going on inside my head with the dialogue, obviously, but in terms of having an arc and Martin between a boy and a man and looking for revenge and a father figure, I didn’t think of all those things.

I am curious about the spaghetti scene. How much spaghetti did you have to eat to get it right? How many takes did you have to do?

Yeah. [Laughs.] That was a mad scene. I had to eat a lot of spaghetti. A lot. I mean, there was a ton of spaghetti going in there. I was trying to keep a straight face for that scene because I just kept laughing. It was just so weird. We did do a lot of takes, and I was just full of carbs and stuff so my stomach was bloating out like a balloon. I was like, "I can’t eat it anymore."

Did it turn you off the stuff forever?

Spaghetti? No, I eat spaghetti and I eat it with that feel and with that scene in mind.

What was your favorite scene to shoot?

My favorite scene was probably the spaghetti. I mean, as an actor, when you do get a scene like that, you get a chance to play around with some stuff. You’re sitting with Nicole Kidman, you get that much dialogue and that prep and that set, and you’re sitting in your boxers. It’s a chance to mess around. As an actor, you don’t get them opportunities a lot—a lot of the time, you’ve got to stick to the paper and you try your own little bit. And with this, it was like, You know what, I’m really going to f--- this one up over its head. I just let loose. There’s a part where I stuck the spaghetti in my mouth and then took it back out. I think Yorgos kept that. Just little things like that.

What was the atmosphere like on set?

It was a very fun, family set. Colin and Nicole were like a mother and father. It was very easy-going. As much of an intense film as this is, it didn’t feel that way on set.

What was your relationship with Colin and Nicole like?

It was great. I mean that. It was great. Two actors of that caliber, the most polite people. As a young actor to sit and watch that, see how they talk to crew and talk to people on set is great because it’s educating me and educating my younger actors as well, beside me, Sunny [Suljic] and Raffey, and then to watch them on screen and see how focused they are was extraordinary.

When did you see the film for the first time?

At Cannes.

What was it like, seeing it there?

In front of everyone? It was tough. It was very tough. I mean, any film you watch with yourself, it’s quite tough. When you’re alone, it’s quite tough, and then when you watch it with that amount of people at the premiere, it was pretty tough. But I was proud. I was very, very proud of this film.

As the film has started to be seen a little wider, what has surprised you the most about people’s responses to it?

Some people dig it, some don’t. I love that. I don’t want to be in movies that show and tell, basically, and have their happy endings. I want to be in movies where filmmakers are telling unique stories and stories that are challenging people and stories that are sometimes not talked about a lot and filmmakers who are unique, so this movie is right down my street. As I watched The Lobster, I loved it. I loved it. I watched it about 10 times. I’m not even messing. So this movie is right down my street, or any movie like this. Any filmmaker who’s willing to speak to their own, tell the stories they want to tell, I’m all for that.

Colin Farrell’s worked with him a bunch of times—would you do it again?

Of course. [Laughs.] In a heartbeat. In a heartbeat.

Margot Robbie is here to show you what vegemite sounds like, in ASMR: