Yorgos Lanthimos’ The Killing Of A Sacred Deer opens with gory, unflinching, seemingly live surgery footage. It’s easily the most graphic moment in his movie, but how stomach-churning virtually every other moment is is testament to Lanthimos’ skills as a master storyteller and filmmaker. He doesn’t need to really show us anything. Words and actions are enough. Particularly when those words are spoken deadpan, by actors who outwardly couldn’t care less.

Colin Farrell’s Steven is a wealthy surgeon with a beautiful wife (played with poise and a steely dignity by Nicole Kidman, who killed it earlier this year in The Beguiled, a Not Quite Horror classic-in-the-making), two great kids and a McMansion to rival even Affleck’s in Gone Girl (though there is, sadly, no footage of Farrell morosely putting out the bins). He also has an odd, ongoing relationship with Martin, a teenager with darkness in his hooded, cloudy eyes.

Over the course of a nerve-shredding two hours, Lanthimos slowly peels back the layers of this relationship, drip-feeding us info until a horrifying proclamation is made and a decision subsequently laid at the feet of the gormless Steven. This Sophie’s Choice-esque predicament doesn’t play out until the film’s final moments, Lanthimos wisely keeping his cards close to his chest, thereby putting the audience in the position of trying to decide for ourselves what Steven should do.

Colin Farrell in The Killing Of A Sacred DeerIMDb lists The Killing Of A Sacred Deer as a horror movie, but it was marketed more as a dark family drama. To be fair, considering how consistently great this year has been for horror, there’s no sense in getting into meaningless arguments over whether Lanthimos’ hugely disturbing film is really horror (it is) or what its inclusion on certain Best Of lists means for the genre as a whole (nothing much — The Witch more than weathered the same backlash).

This is horror in its purest, most distilled form, freed from the shackles of jump scares or exposition. Even without that gut-churning final act moment, there’s enough weird, creepy, disconcerting stuff in The Killing Of A Sacred Deer to make your skin crawl, whether it’s Steven’s predilection for making love to his wife while she pretends to be comatose, or the way his daughter strips for Martin and lies down on the bed in much the same way to present herself to him like an animal in heat.

Martin is the movie’s ace card, a supremely frightening yet weirdly charismatic creation who makes even the act of eating spaghetti seem terrifying. Clearly a sociopath, he first uses his naivete to lure Steven into a false sense of security, entering his home and charming his family, before letting him know, in the plainness of the hospital cafeteria, that he’s really the one in control. He waits outside the house in plain view, unmoved by being spotted, arrogant in his complete belief in his own power.

Nicole Kidman in The Killing Of A Sacred Deer

As Martin, Irish actor Barry Keoghan gives his best, most self-assured performance to date, in a career that up until now has mostly seen him playing second fiddle in the likes of Dunkirk and Mammal, where he stretched his weirdo muscles. His mouth curls around the American vowels as though it can’t quite force them out (his heavy north Dublin accent threatens to come out when he’s using the word “father” in particular) but his steely, focused glare remains immovable.

He’s the perfect foil for the smug Steven, a man whose profession has allowed him to play god for who knows how many years and, when he finds himself losing control over his own life, simply cannot handle it. Kidman does great work as his tortured wife, but this is essentially a two-hander between Farrell and Keoghan, both men jostling for supremacy amidst the escalating drama.

Lanthimos based The Killing Of A Sacred Deer on the Greek myth of Iphigenia, who was offered as a sacrifice (by her own father, no less) to satisfy the goddess Artemis after he had offended her. His tale is somehow darker, and more damning of its characters, which makes the take-no-shit ending even more of a gut punch. It’s horror through and through, and if you missed it this year, you owe it to yourself to catch up. You’ll probably leave the film feeling like you need a shower, which was surely the intention.