Thoroughbreds.

Thoroughbreds (amazon • iTunes) is sort of Discount Heathers, with a girl playing the disaffected provocateur role, and a lower body count, plus an ending that doesn’t quite hold together as tightly as its obvious inspiration. Even with some of its flaws, however, it’s so tightly written and features two riveting performances by its leads that it’s worth seeing even if you, like me, have fond memories of the 1988 darkly comic original.

Thoroughbreds starts out with the two teenaged protagonists reuniting after several years apart, meeting as Andover student Lily (Anya Taylor-Joy) begins to tutor the peculiar Amanda (Olivia Cooke), the latter of whom has apparently just killed her horse. Amanda has exceptional perception and quickly sees through Lily’s pretenses, while also confessing to extreme emotional detachment: Amanda is anhedonic and perhaps antisocial, feeling nothing whatsoever and showing it in her perpetually neutral expressions. Her gaze and her tone are both disarming, which leads to the first of many funny scenes when Lily finally cops to the fact that Amanda freaks her out.

The plot kicks into gear shortly afterwards when Amanda suggests to Lily that she kill her controlling and vaguely creepy stepfather, Mark, who is very wealthy and berates Lily’s ineffectual mother. (Although I thought the film implied early in the script that Mark was at the least leering at Lily, if not actually attempting to abuse her, that turned out to be wrong, and Mark is just an asshole, but not a criminal.) Lily is aghast at the idea, until she sees Mark verbally abuse her mother again and finds out he’s decided to send her to a different boarding school, after which she tells Amanda she wants to go through with it. They plan to use a lowlife drug dealer, Tim (Anton Yelchin in what I think ended up his last film role), as hitman, although his willingness and his competence are both open questions. As the plan progresses, it turns out that Lily isn’t quite the delicate flower – or lily-white princess – she appears to be.

Taylor-Joy is perfect as Lily, embodying both the perfect little white girl persona and the stuck-up prep school teenager, but it’s Cooke as Amanda who grabs the wheel and steers the movie all the way to the big finish. Cooke has to be convincing as this weary, wise, incisive kid who is fooled by nobody and who rigorously applies logic to every situation, including understanding why people will act in specific ways and how to use that to their advantage. And she is, to an exceptional degree – her delivery is so dry, and her face so impassive, that Cooke sells Amanda as a teenaged automaton, making everything that comes afterwards credible, because nothing in this film works without that character. Taylor-Joy works, and it wouldn’t surprise me if she had the bigger career of the two, but Cooke has this film by the throat and never lets go.

Cory Finley made his debut as both director and screenwriter with Thoroughbreds, crafting those two compelling characters and working in plenty of very dark humor, although he seemed unsure of how to stick the landing, and the film wobbles as a result before more or less staying on its feet. Amanda’s motivation at the climax is unclear or just hard to accept, and the brief coda doesn’t add anything to the story; ending the film in the final shot with Lily and Amanda together would have been more effective. There are also some extremely strong and unsettling shots of the girls’ faces that add to the noir-ish feel of the film without interrupting its flow. It’s a very auspicious first effort for Finley, however, marking him as a filmmaker to watch, as well as a star turn for Cooke.