“Interesting” is such a polite, lukewarm, colorless word. And given that Brady Corbet‘s arrestingly ambitious “Vox Lux” is about as polite, lukewarm, and colorless as Natalie Portman reimagined as a foulmouthed Ariana Grande sporting a spangled catsuit and a God complex, it is scarcely adequate here. But it does speak to the great strides that Corbet has made since his debut, “The Childhood of a Leader,” which went similarly hell-for-leather at its grandiose agenda, but for quite long periods managed, noisily and show-offily, not to be that interesting at all. “Vox Lux,” in which the flaws are so unapologetic they’re almost virtues, displays a lot of the same preoccupations as ‘Childhood’ but is a far better film, glitchy yet absorbing, panicky yet strangely wise.”Interesting” sounds too much like faint praise, for a film as actively, chewily unboring as this one. So “unboring” it’s going to have to be.

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Though his touch is lighter, more self-aware and more spicily ironic than with the sludgily self-serious ‘Childhood,’ Corbet’s intent here is just as monumental and peculiar: to relate the plastic vacuity of modern pop stardom to the seismic shifts in American society that have happened since Columbine, 9/11, and the dawning of the Age of Terror, and in so doing to dignify millennial celebrity culture in a jaggedly artful way that few, if any, other films have attempted. And so “Vox Lux” has a brilliantly shot and profoundly terrifying prologue, set in 1999 (the year of Columbine), during which a boy with a scrubbily shaven head, eye make-up, and machine gun walks into a classroom and coolly shoots the teacher dead before ordering his schoolmates to line up at the back of the room.

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One of them refuses, or is she paralyzed with shock? She is 13-year-old Celeste (Raffey Cassidy) and she’s the only one who pleads with the shooter to spare them. It makes him hesitate, the way she addresses him, directly and with compassion. But then he opens fire anyway. The low-to-ground footage of the ambulance screaming to the hospital with a blood-soaked Celeste inside feels like a ’70s slasher film (indeed, Lol Crawley‘s darkly grainy 35mm camerawork, and Scott Walker‘s brilliantly discordant, apocalyptic scoring gives the whole first half an aesthetic that evokes “The Omen” or “The Evil Dead“). And over this horror-movie opening, the credits play — a full credits roll, giving the beginning of the film, which depicts the end of so many lives, an appropriately terminal feeling.

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During “Act I: Genesis,” Celeste survives and recuperates, her devoted older sister Ellie (Stacy Martin) vows never again to leave her side, and at a memorial service for the victims they perform a song they wrote together (a melodic ballad written, like all the songs performed in the film by executive producer Sia). The TV coverage of that performance gets the innocent and sweet-natured Celeste a manager (Jude Law, looking rightly dissipated and disheveled) and a recording deal, plus a publicist (Jennifer Ehle). With Willem Dafoe’s gravelly, sardonic voiceover occasionally checking in with updates from the inside of the characters’ psyches as though he’s reading incident reports from a police blotter, this progression is made to feel normal, natural even, like it’s somehow predestined.

By the time “Act II: Regenesis” rolls around, it’s 2017 and Celeste is now played by an unprecedentedly spiky Natalie Portman, with a Staten Island accent so broad you need a ferry just to get across it, a recent scandal that has seen her lying low for a while, and a daughter of her own, Albertine also played by Raffey Cassidy. (As mentioned, some of Corbet’s flourishes are more perplexing than successful and this recasting, when Stacy Martin continues to play Ellie, is one of them, as is the sudden appearance of an accent that Celeste did not seem to have as a child.) Celeste is about to play a “comeback” gig in her hometown of New Brighton when news breaks that a mass shooting in Croatia has been incidentally linked to her music.

The twin strands run in parallel, really, the paranoid hubbub of the world outside and the soap-operatics of Celeste’s life as a bitchy pop prima donna. But wrapped up in Portman’s like-it-or-loathe-it-you-cannot-ignore-it performance (I love it, for the record) and Corbet’s astonishingly confident filmmaking chutzpah — all fast-motion montages, off-kilter framing, and bravura soundtrack collisions between Walker’s score and Sia/Celeste’s pop tracks — it somehow becomes a jagged, messy but endlessly intriguing whole. Proving Corbet’s credentials as a filmmaker never afraid to risk doing something wrong for the sake of doing something interesting, even the climactic show, which by any measure goes on way too long, starts to work its own mesmeric magic, becoming, in its own right, somehow important in the grand frivolity of its spectacle and escapism.

It’s not every filmmaker who gets to learn by doing, with all the resources that Corbet has to hand, and with a traffic cone apparently holding his parking spot in the Venice Competition at the end. But he seems intrinsically aware of his good fortune and determined not to squander it by giving less than everything to every new project, and so he perhaps earns the luxury of learning as he goes. Certainly, the steep upward trajectory represented by the leap in quality between his first and second films suggests, though “Vox Lux” is not it, he is comfortably en route toward the truly great film he’ll one day make. And in the meantime, he’s doing his impressive, sincere best, for those of us spectating, to make the journey interesting. Or rather, exceptionally unboring. [B/B+]

Check out all our coverage from the 2018 Venice Film Festival here.