Three people sit together at a bar, a man and woman caught up in an animated conversation we can’t hear and another guy looking sad or bored or anxious as he nurses his drink in silence. From across the room, the voices of two unseen people speculate on who the three strangers are to each other, a game that writers often play, basing their guesswork mostly on body language and on the simple fact that they’re out at a New York bar in the early hours of the morning.

The teasing suggestion for a moment is that the film will reveal the faces behind those voices and that perhaps they will even be protagonists. But when the camera moves in for an intimate closeup of the woman across the bar, deep in a thought that seems to take her someplace far away, it’s clear she will be the story’s gravitational center.

That opening scene in Past Lives, the remarkably assured debut feature from playwright Celine Song, is a clever prologue that piques our interest while barely even hinting at the roiling emotions to be stirred up when we return to the same scene, this time within our earshot, late in the film. That happens long after the identities of the three people and their intricate connections have been established.

The principal characters are drawn into a melancholy triangulation, but this is no banal romantic triangle drama. It has interludes of soaring romance that will make you catch your breath but is rigorous in its avoidance of melodrama.

It’s difficult to convey the multilayered beauty of Past Lives beyond just urging people to see it and lose themselves in its transfixing spell. So if you want that experience in its purest form, stop reading here and just trust me that the A24 release is an exceptional movie, destined to have a life long after its rapturously received Sundance premiere and upcoming Berlin competition slot.

In keeping with Song’s themes, it’s likely that the movie will also reach back into your own life, prompting you to ponder forks in the road and consider how a different course might have altered your identity.

To the extent that its complexities can be condensed, the film is a probing contemplation of love and fate; stinging regret over life choices; wondering where different choices might have taken us; and acknowledging the hole left in our lives by that phantom parallel existence, even while remaining steadfastly convinced that the choices made were the right ones. Its reflections will likely keep haunting you for days.

Song’s elegant script is structured as a triptych, shifting gracefully through three time periods covering more than two decades across two continents. The story begins 24 years before the bar scene, jumping to South Korea, where 12-year-old Nora (Seung Ah Moon), still going by her birth name Na Young at that time, is preparing to emigrate with her family to Canada. She’s academically competitive with her best friend from school, Hae Sung (Seung Min Yim), sobbing when he ousts her from first place in a class assignment.

In a lovely scene that will be echoed later in the movie, Nora’s mother (Ji Hye Yoon) accompanies the two children on a playdate to a park, wishing to create memories that will stay with her daughter as she adapts to her new North American life. One shot in particular will continue to resonate, with Hae Sung staring solemnly out the car window on the way home after Nora has fallen asleep on his shoulder. There’s an unexpressed dolefulness in his brief goodbye to his childhood crush, whereas she seems matter of fact about it, unsentimental, having precociously mapped out a future as an award-winning writer.

Twelve years later, Nora (now played by Greta Lee) has relocated from Toronto to New York to study playwriting. Curious about what’s become of the people she knew back in Seoul, she starts searching online, at first struggling even to remember the name of the boy who was her closest companion. When she finds Hae Sung (Teo Yoo), she discovers he’s also been seeking her out on social media. The two begin communicating online, with Nora’s rusty Korean indicating the extent to which her cultural identity has changed.

When they switch to Skype calls, initial shyness quickly gives way to warmth and spontaneity, even though Nora’s easygoing Americanized personality is quite distinct from the more reserved manner of Hae Sung, now studying engineering. Their conversations grow in intensity to the point where they start discussing a physical reunion. But for various reasons, Nora pulls back, as she prepares to go to a Montauk writers’ colony while he goes to China to learn Mandarin.

In Montauk, Nora meets another writer, Arthur (John Magaro). Half drunk on moonlight and wine, she talks to him about the Korean concept of In-Yun, pertaining to fate and relationships, specifically connections between two people informed by countless connections in their past lives. Then she laughs it off: “That’s just something Koreans say to seduce someone.”

Twelve more years pass. Nora has been married to Arthur for the last seven of them when she hears from Hae Sung out of the blue that he’s finally coming to New York for a vacation. At their first encounter — significantly in a park — Hae Sung stands smiling but remains stiff and uncertain until Nora breaks the ice with a lingering hug. It’s a moment so loaded with unspoken feeling it’s almost emotionally overwhelming. Pretty much all they can say to each other at first is “Whoah!” But they begin filling in the gaps and falling back into their old closeness during a riverside walk in Brooklyn.

There are any number of predictable ways a less subtle writer and filmmaker might steer this reunion — about soulmates reconnecting or a woman facing a difficult, potentially life-changing choice or two men competing for the love of the same woman. But that’s not Song’s film. Her choices remain unexpected right through the ravishing final section, which includes the opening scene of Nora, Hae Sung and Arthur at the bar.

The director’s background in playwriting is evident in her impeccable skill with scene structure and dialogue — not to mention her personal investment, given that the script sprang out of her own mind-bending experience of finding herself sitting between her husband and her childhood sweetheart in a New York bar.

One of many standout scenes is Nora’s account to Arthur of her first day spent with Hae Sung when she gets back to their apartment that evening. “He’s very Korean,” she says, in a tone that implies both amused ambivalence and respect for that cultural stamp. She sees herself as not Korean when she’s with Hae Sung, “But in some ways more Korean.”

The sense of how places, cities, architecture and cultural mores shape and change people over time is deeply embedded in the limpid cinematography of Shabier Kirchner (who shot Steve McQueen’s Small Axe films), its naturalistic gaze somehow managing to be both detached and intimate.

Some clever misdirection makes us underestimate Arthur’s emotional acuity for a minute — he’s published a novel called Boner and spends time alone playing videogames like a kid. But in Magaro’s thoughtful, quietly heartbreaking performance, we come to see the internal struggle between jealousy and grownup acceptance of Nora’s need to revisit and understand a forgotten part of her past. One of the most admirable qualities of Song’s film is the uncommon fairness and generosity with which she treats all three principal figures, even if the dominant perspective is Nora’s.

Arthur gets almost meta about the situation during a conversation in bed, imagining Hae Sung’s resurfacing as a story in which he would be “the evil white American standing in the way of her destiny.” When he reveals to her that she sleep-talks in Korean, his sense of exclusion is palpable, even if he’s been learning the language. “It’s like there’s this whole place inside you where I can’t go,” he tells her, confessing that he wonders if his life can ever be big enough for her.

When Nora’s husband and the reanimated ghost from her past finally meet on the visitor’s last night in town, Arthur’s anxiousness over the obvious connection between his wife and Hae Sung is achingly poignant. But so too is Hae Sung’s confession of the hurt that liking Arthur causes him. During a gorgeous moment when the two men are briefly alone together, Hae Sung ventures that In-Yun — a theme that has been percolating through the film — applies to them, too. The emotional fortitude required for Hae Sung finally to open up to Nora and articulate his feelings is enormous, and yet Song and her actors play the scene with unerring restraint. The same goes for the concluding stretch, which is both gut-wrenching and consoling.

The performances of the three leads simply couldn’t be better. This stands to be a breakout role for Yoo, who draws a line with great sensitivity from the 12-year-old boy standing silently alongside a weeping Nora to the insecure yet hopeful young college student, out getting drunk with his buddies on soju but still living at home with his parents. In the closing section, he becomes the mature man finally able to act on feelings that have been with him most of his life, and with even more difficulty, to express them. The character’s evolution, and Yoo’s ability to convey it often with just his eyes or his body language, is soul-stirring.

It’s wonderful to see Magaro, so superb in Kelly Reichardt’s First Cow and Showing Up, in a romantic role. He has the least screen time of the three leads but manages the tricky balance of finding both humor and pathos in his character. Magaro makes the part into something profound and complex via the gentleness of Arthur’s demeanor and the evident pain of maintaining an adult calm and understanding amid developments that could potentially break him, letting just a peak of resentment show through.

What to say about the extraordinary depths of Lee’s performance? She makes you live inside Nora’s head for the duration, tending to let the character’s intelligence prevail over her emotions to the point where her one moment of raw release will rip you apart.

There’s so much going on behind Lee’s eyes that you’re aware of Nora being transported, caught up in the what-ifs of another life and saddened by the awareness of that untraveled path always occupying an empty space inside her. She’s a modern woman who knows exactly who she is, ambitious and self-possessed, so when she surrenders to feelings of wistfulness, of existential longing, it’s profoundly moving.

Song reveals herself to be a fully formed filmmaker with this accomplished debut. She shows a visual command to match her emotional and philosophical insights, a pleasingly understated wit and a grasp of tone that never falters, enhanced by the delicate chiming synths of a score by Christopher Bear and Daniel Rossen, from indie rock band Grizzly Bear. The fluency with which the writer-director moves between time periods and distant places is impressive indeed, with invaluable help from Keith Fraase’s supple editing.

For a movie in which the characters often dance around their feelings without directly addressing them, Past Lives speaks volumes. It’s only January, but there’s no doubt it will be one of the best films of the year.