‘Thoroughbreds’ a thoroughly fun, smart, psychological horror flick

Playwright-turned-filmmaker Cory Finley makes an impressive debut with “Thoroughbreds,” in which he makes us feel something for a character who can’t feel anything at all.

And for her friend, who feels too much. That would be Amanda (Olivia Cooke) and Lily (Anya Taylor-Joy), respectively. They’re rich girls growing up in suburban Connecticut. We meet Amanda as she is about to kill her horse (like most of the violence, we don’t see the act).

We meet her again when she shows up at Lily’s mansion — estate, really, courtesy of her much-despised stepfather, Mark (Paul Sparks) — for tutoring. They used to be friends, but brutally murdering your horse and having the pictures go viral tend to diminish your social life a little. Amanda’s mother is paying Lily for the job and for a little friendship on the side, a transaction that works a little too well and takes off in unexpected directions.

There is probably a version of a story with characters like this in which the two halves come together to form a healthy whole.

This isn’t that.

Instead it’s an expertly directed, slow-burning psychological horror film filled with outstanding performances (including the last by the late Anton Yelchin as the most pathetic would-be hit man you’ll ever see).

Amanda is up-front about her feelings, or lack thereof. She simply cannot feel emotion: no joy, no sadness and, obviously, no remorse. “It doesn’t mean I’m a bad person,” she says. “It just means that I have to try harder than everyone else to be good.”

And she does try. She seems to enjoy Lily’s company, and Lily likes her coming around (the two were childhood friends). Certainly, Amanda isn’t going to judge her. Plus, Lily can learn from Amanda, too. Because she would never genuinely be moved enough to cry, Amanda has learned to make herself cry on command, and she teaches Lily the trick. It’s handy when your stepfather is a self-centered jerk.

Not that he cares about Lily’s tears. At first, Mark seems as unfeeling as Amanda, until you realize he cares deeply — about himself, no one else.

The talk between Amanda and Lily leads in the direction Finley, adapting his play, has been leading us all along: What if they killed Mark? With any other teenage girls, it would be drama-queen fantasy, but these aren’t any other teenage girls.

Of course, they don’t want to do the deed themselves, which is where rumored pedophile and definite drug-dealer-to-kids Tim comes in. Yelchin plays the character as a born loser with big plans — you just wait, he may be dealing nickel bags to high-schoolers now, but in a couple of years, he’ll be dealing all up and down the East Coast.

Nothing goes as planned, of course, and Finley fills the movie with dark humor. What happens doesn’t matter so much as how it happens — the performances and the direction drive the film. Cooke is terrific, having to register everything in small movements and facial reactions. (She doesn’t feel anything, after all, so she has to express everything in non-traditional ways.) Taylor-Joy is just as good as her opposite number, a supposed good girl with her own problems.

Cinematographer Lyle Vincent makes the beautiful seem obscene — most of the film is set in Lily’s mansion. The use of sound, whether jarring or … well, mostly jarring, really, is exceptionally effective in putting us on edge, so that the most-minimal human transaction (and most of them are minimal) creates tension.

Finley frames shots just so, holding stares and poses just long enough to draw attention to what he’s doing, no more. It’s a most-promising debut, a film that keeps you off-balance and uncomfortable — which, as any real horror fan knows, is just where you want to be.

Bill Goodykoontz, USA TODAY Network

★★★

Focus Features presents a film written and directed by Cory Finley. Rated R (for disturbing behavior, bloody images, language, sexual references, and some drug content). Running time: 90 minutes. Opens Friday at local theaters.