“Fingernails” is a romantic curiosity with a touch of sci-fi, a film that puts The Observer Effect in a human relationships context. That’s the physics phenomenon/theory that you change something merely by the act of studying or “observing” it.

This Christos Nikou tale imagines a not-really-alternate reality in which loneliness has reached the “crisis” stage, science has allegedly discovered a chemical compatibility test that requires a full, yanked-out fingernail to be processed and two co-workers at a counseling “Love Institute” start to wonder if they’re with Mr. or Ms. Right, thanks to mutual attraction, no matter what science tells them.

Can “true love” be tested by yanking and cooking fingernails? Can any romance stand up to cold, hard scientific or pseudo scientific scrutiny?

It’s the sort of movie you get when an off-center Greek filmmaker co-writes and shoots an Anglo-American produced romance in the overcast fall of Ontario. It’s just a tad…off.

Only the players give it any hint of warmth or heart, because this dry-to-the-point-of-parched “love story” is hellbent on avoiding that.

Jessie Buckley stars as Anna, a school teacher who some while back “tested positive” with her longtime beau, Ryan (Jeremy Allen White). But as their relationship has settled into routine, he feels the freedom to unemotionally note anything he doesn’t like. And when he’s not around, she’s free to admit that she’s “sacrificing” little things about herself to indulge him.

They mix and mingle with other couples, the “tested” and the untested. Although the movie limits this alternate reality by leaving out all of the reasons for our global epidemic of loneliness and romantic ennui — “media” is limited to nature documentaries and old movies, “social” media apparently doesn’t exist — Nikou immerses us in a world of brittle relationships and the fragile people trapped in them, or struggling to find one that “tests positive.”

Anna’s journey truly begins when she abandons her chosen profession for a job at The Love Institute, whose founder (Luke Wilson) wants to go beyond the breakthrough fingernail-testing that takes “the risk out of love” and do therapy and exercises with couples that “make the bond of love stronger.”

The “tests” would be amusing bits of comic quackery in another filmmaker’s hands. The “smell” test has couples urged not to bathe for a day or two, show up, strip to their underwear and wear a blindfold to discover if they can work the room, and sense their beloved through smell.

Underwater “one minute of eye contact” while holding one’s breath in a pool? Measuring partners’ reactions to “Notting Hill” in a local cinema (with Our Founder wanting to amp that up by staging a fake fire in the theater to gauge reactions and whether or not partners put their lovers ahead of themselves) is another.

Tandem skydiving? Sure

But Anna is paired-up with the cynical, wry trainer Amir, who seems to see through the crackpottery of it all. He notes precautions to take with the underwater exercise.

“Don’t want anyone dying on us...again.”

As Anna loves to ask people about their romances, their “how you met” stories, Amir invents a corny one about how he met his Natasha, and admits the joke. Because that’s what cynics do.

We can see Anna break out in Buckley’s adorable crooked smile, the spark between them as they work with inspiringly-devoted young lovers and worrisome, untested other couples. And that’s contrasted with the drab, incurious love life Anna faces at home at the end of every day.

She even tries to trick Ryan into taking this or that test, a trite sitcom plot device, but at least one that promises something lighter.

But Nikou — you just knew a “Dogtooth” trained Greek whose quirky first film was titled “Apples” was going to make a movie for Apple — isn’t having it. There’ll be little lightness here, and when there is, it’s as if he resents having to include it.

The entire production feels a tad stiff, as if he’s scientifically market-tested how he can approach this (a LATE third act single moment inclusion of a same-sex couple) and just checking off boxes along the way, making a movie that feels like a product of the alternate reality he’s presenting.

But Buckley, of “Lost Child” and “Wild Rose,” and Ahmed (“Sound of Metal,” “Nightcrawler”) make the characters more interesting than the scripted story they appear in. There is a hint of romantic warmth here, and it all comes from them.

Rating: R, a bit of violence, profanity

Cast: Jessie Buckley, Riz Ahmed, Jeremy Allen White and Luke Wilson

Credits: Directed by Christos Nikou, scripted by Christos Nikou, Sam Steiner and Stavros Raptis. An Apple TV+ release.

Running time: 1:53