Unlike the Miami transit service that gives the film its title and gets from first to final stop in just 16 minutes, Omni Loop takes time to wade through its tangled thicket of set-up and draw you in. But Bernardo Britto’s near-future sci-fi — about death, time travel and the cherished gifts in life we take for granted while pursuing that elusive something more — sneaks up on you. The same goes for the expertly synced performances of Mary-Louise Parker, bringing her characteristic flinty authenticity to a role that could easily have drowned in quirk, and Ayo Edebiri, demonstrating once again that she’s in the top tier of emerging American actors.

In a brief prologue, a 12-year-old girl (Riley Elise Fincher-Foster) stumbles upon a bottle of pills on the greenest of fields. “You’re gonna do incredible things one day,” a voice in her head tells her. “You’re gonna change the world.” While the girl’s identity is easy enough to intuit, the full circumstances of that pivotal moment and the person behind the prophetic voice she hears are revealed only in the concluding stretch. By that time, the episode has built a powerful emotional pull — even if not all the plot holes are tidily filled.

Britto’s Groundhog Day variation has Parker’s Zoya Lowe, a once-promising quantum physicist at Princeton, endlessly reliving the same soul-deadening five days that follow her release from the hospital with a terminal diagnosis.

Her college-sweetheart husband Donald (Carlos Jacott), their adult daughter Jayne (Hannah Pearl Utt) and the latter’s fiancé Morris (Chris Witaske) are informed by Zoya’s doctor that the black hole in her chest is inoperable and that she likely has a week at most left to live. The medic advises the bereft family to take her home, make her comfortable and provide whatever distractions they can to keep her from dwelling on her mortality.

But Zoya, whose numbness bordering on annoyance slowly starts to make sense, knows every detail of what’s to come — the reluctant meeting with her publisher over a modern physics textbook; the updating of her will; the visit to her nonverbal, cognitively impaired mother (Fern Katz) in a care home; even the conversation on a garden bench with another resident and the exact moment a bird in the tree above will drop a splat between them. The same goes for the surprise early 55th birthday celebration her family organizes.

Before she blows out the candles, a nosebleed signals her imminent disappearance, prompting her to pop another pill and wake up in hospital the next morning to start the whole cycle again.

But a chance encounter with Paula (Edebiri), a young woman studying time in a college lab, changes everything. That meeting galvanizes Zoya to break the cycle’s routine by teaming up with Paula to resurrect her abandoned research from her Princeton days and solve the enigma of time travel so that she can go back into her past — before she “settled” — and redirect her life to find the fulfillment she lacks.

Given that the time loop exists only for Zoya, that means having to start from scratch every day, convincing Paula over and over that she’s not a nutjob. Edebiri conveys the initial skepticism of each new beginning with low-key humor, but she gives the character a driving curiosity and open-mindedness that make her willingness to dive into Zoya’s research fully plausible. For her part, Paula also has a personal stake in the time-travel conundrum — her gnawing remorse over something she did in her youth that indirectly resulted in tragedy.

The future depicted in Omni Loop (the year is unspecified) is barely distinguishable from our own, clearly by design. The science stuff — the puzzling over impossible equations, the attempts to break down the complex structure of the self-regenerating reset pills — drags a little in the early stages, even with the director’s crafty low-tech solutions to depicting future technological developments like the ability to shrink humans. But all the physics talk steadily becomes less important to Britto’s investigation of what gives a life meaning, just as it becomes less important to Zoya.

What keeps the movie engaging is the rapport between the two women, and the way their mutual support and compassion slowly shifts their focus. Their heart-to-hearts at the end of each day, just before Zoya’s nosebleed stops the clock, are especially poignant, played with deep feeling by both actors. Among the more affecting scenes is Zoya’s visit to the home of a brilliant former Princeton associate and her sad exchange with the man’s son (Steven Maier), during which she learns that her inconclusive research left more of a mark than she believed.

Despite its high-concept premise and lengthy spells of laboratory work, Britto’s movie is fundamentally an intimately humanistic exploration of death and acceptance. As Kaitlyn Aurelia Smith’s score gradually evolves from needling electronica into more emotional, melodic moods, Zoya starts to see things differently, devoting more of her remaining time to her family and reaffirming her gratitude for what each of them has given her.

A quiet pillow-talk scene with Donald is gorgeous, as is a wrenching moment toward the end with the family gathered around the dinner table. There’s also a lovely sense of intergenerational generosity, as two sharp scientific minds pool their knowledge, and ultimately, as Zoya instills confidence in Paula to continue her work.

Perhaps a line or two to explain how Zoya has been reliving the same five days and yet has somehow advanced four decades since she first started taking the pills wouldn’t have hurt. But that’s just a quibble. The movie’s message — about owning your choices and appreciating what you have rather than what you might have wished for — plays out as a comforting balm.