Fingernails review: a beautifully eccentric depiction of the mysteries of love

What is love? Cinema has spent a considerable time pondering that question, though one thing is for certain: love is uncertain. To love is to risk both the joy of reciprocity and the pain of rejection; that it might last or fade, work out or not, or not be with the one.

That's the entry point for Christos Nikou's latest quirky endeavour; a sweet comedy set in an American society where romantic unpredictability can be avoided thanks to a controversial test to decide whether couples are truly in love.

It's a concept that was recently explored in the Prime Video series Soulmates, but the Greek filmmaker brings the existential dry wit he established in his excellent debut Apples to poke holes in our technological and pop-culture-obsessed world through the endearing eyes of Jessie Buckley's Anna.

Anna and her boyfriend of three years Ryan (Jeremy Allen White) passed the test but she's feeling uncertain while he has become complacent. "Even if sometimes our relationship settles into routine, we don't need to question that," Ryan tells an enquiring friend at a dinner party, the camera closing in on Anna's face to show her disappointment.

An unemployed primary school teacher, she secretly begins working at the local love testing institute to understand more about the process. There she meets Luke Wilson's somewhat jaded founder Duncan and Amir (Riz Ahmed), an earnest diagnostician claiming to be in a happy relationship.

From watching Hugh Grant rom-coms to electro-shock therapy, Amir has developed exercises to improve couples' bonds and their chances of passing. These scenes are hilariously deadpan and while the love training relies on these clichés, the script – co-written by Nikou, Sam Steiner and Stavros Raptis – refreshingly avoids them in favour of a more natural, understated approach.

Furtive glances, smiles and growing awkwardness between Anna and Amir indicate a growing attraction, and Buckley and Ahmed's chemistry is gorgeously tentative. White's romantic indifference, however, is not cold, more lukewarm, ensuring Ryan doesn't fill the role of a typical rom-com villain – his sad boy eyes make certain of that.

The world-building here is nostalgically quaint, and there's a humour to the exuberance of love being quantified in such a mundane office space. A rain track is played through speakers because it "makes people feel romantic." The soundtrack features Total Eclipse of the Heart, a radio request dedicated to a couple after they failed the test. Pre-test couples listen to La Mer and a French version of Only You, because the language is more erotic, offering a lyrical playfulness and compounding the tropes being picked apart.

Fingernails doesn't have the answer to that age-old question of how you know. But it delivers a beautiful and eccentric articulation of the painstaking feeling of throwing yourself into the romantic unknown all the same.

In cinemas, on Apple TV+ from November 3