Boasting themes that are both cerebral and philosophical, “Before I Fall” is a young adult thriller that goes far beyond the surface level. Too often teenagers — girls, especially — are depicted on screen as superficial, obsessed with appearances and the happy-go-lucky lifestyle enabled by parental disposable income. But in “Before I Fall,” popularity contests are plagued by truly existential conundrums, with elevated stakes exacerbated by the fleeting nature of youth, and questions about the nature of life itself go hand in hand with the tricky maneuvering of high school politics.

There’s a supernatural-ish twist that kicks off all of this questioning. “Before I Fall” borrows a premise from “Groundhog Day,” in that our protagonist, Samantha (Zoey Deutch), must relive the same Friday, over and over, preceding a dangerous car crash. To make matters worse, it’s Cupid Day, wherein the entire high school celebrates Valentine’s Day with “val-o-grams,” rose deliveries that literally account for every student’s popularity points.

Sam starts off as a carefree queen bee, ensconced in a tightly-knit foursome of popular girls, with closely held allies and enemies. However, forced to relive the day over and over, which resets at the moment of the crash every time, she zeroes in on the side characters, the nerds and the bullied, and the small interactions that lead toward the inevitable, trying to change things and stop the loop.

Adapted by Maria Maggenti from Lauren Oliver’s novel, and directed by Ry Russo-Young, “Before I Fall” is an anomaly in that it focuses on the deeply intimate friendships between teenage girls, foregrounding their experiences, their voices, and their perspectives among the hubbub of high school. Boyfriends are present, but not as important as the bonds between girls, born of shared history and hours spent together, an in-between tribe bridging family and college.

As Sam, Deutch is supported by the likes of Halston Sage as uber mean girl Lindsay, using her armor as a weapon, Logan Miller as longtime pal Kent, and Medalion Rahimi and Cynthy Wu as the rest of her clique. But this is Deutch’s film — she carries the emotional journey on her back, as Sam is the only one who knows she’s in a doomed time loop.

In the course of living our lives, we can’t go back and re-do a terrible high school party, or a bad day, or a moment where we wish we had extended a kindness instead of something else. Sam is able to do that, and as she makes another circle around the track, she learns something every time. We might not get do-overs, but “Before I Fall” is reminder of how growth, change and breaking with norms can bring us to our truest selves.

MOVIE REVIEW

“Before I Fall”

Grade: B

Starring Zoey Deutch, Halston Sage and Jennifer Beals. Directed by Ry Russo-Young.

Rated PG-13 for mature thematic content involving drinking, sexuality, bullying, some violent images, and language-all involving teens. Check listings for theaters. 1 hour, 39 minutes.

Bottom line: A young adult thriller with truly existential conundrums