AUSTIN, Texas - Following in the footsteps of “Sound of My Voice” and “Martha Marcy May Marlene,” the indie world’s fascination with cults – or cult-ish behavior – continues at the 2012 South by Southwest film fest with Rebecca Thomas’s “Electrick Children,” a quirky portrait of two Mormon teenagers searching for meaning in suburban Las Vegas.

Inspired by the filmmaker’s own experiences as a Mormon growing up outside Sin City, the film explores faith in delicate, sensitive ways, particularly in the face of secular temptation. But it eventually acquiesces to indie-film clichés instead of digging deeper into its intriguing philosophical quandaries, ultimately creating a portrait of divine providence that’s more promising than profound.

Julia Garner (perhaps ironically, “Martha Marcy May Marlene”) plays Rachel, a devout teenager who gets introduced to the world beyond her insular Mormon community after her father Paul (Billy Zane) records her religious testimony on a tape recorder. Fascinated by the mysterious technology, she sneaks out to listen to it at night, and among the interview recordings she finds a cassette tape with music on it – the first rock & roll she’s ever heard.

When her brother Mr. Will (Liam Aiken) intercedes to stop her from playing it, their mother, Gay Lynn (Cynthia Watros), catches both of them and lets them off with a warning. But when Rachel announces several weeks later that she believes she’s become the benefactor of an immaculate conception, Paul and Gay Lynn blame Will and cast him out of their community.

Despite Rachel's protests of innocence to “the ways of men,” Paul arranges a wedding for her and she is scheduled to be married before she gives birth. But the girl makes off in the family truck and heads for Vegas, where she hopes to find the singer of that rock song – whom she assumes is the father of her child – even as Will follows hot after her, hoping she’ll confess to lying so that he can return from exile. Instead, Rachel meets a burnout named Clyde (Rory Culkin) who shows her the ways of the secular world, and she and Will are soon forced to choose whether they want to remain with their new friends or reunite with their family.

Well-directed by Thomas and extremely well-acted by Garner, whose fresh-faced enthusiasm gives Rachel exactly the wholesome untouchability that she needs, “Electrick Children” feels perhaps more like a series of great discoveries than a single significant accomplishment. In early scenes, Thomas’ script treats its Mormon community like it’s an outpost on Mars, but the writing never succumbs to judgment or bland stereotyping of the religion’s values -- even when Paul almost indifferently blames Will for Rachel’s pregnancy, and especially when she insists that she got pregnant by listening to a rendition of The Nerves’ “Hanging on the Telephone.” Garner’s performance, meanwhile, never veers into preciousness or pure naivete, instead giving Rachel a modicum of common sense even when she’s marveling at the conveniences of modern technology.

That said, the journey that Rachel undertakes never achieves any deeper resonance, because her faith is essentially never challenged. Although Clyde and his friends initially look mockingly upon her unlikely assertions, her misadventures feel more like a weekend getaway than a genuine, epiphany-inspiring crisis, not the least of which because almost nothing of consequence happens to her –- good or bad – to give her a more realistic perspective on the world, or even reassure her that what she believes is correct.

It’s sort of the difference between plot and story, and there’s plenty of the former and not enough of the latter; even when she makes some “important” discoveries about the singer of “Hanging on the Telephone,” they scarcely impact her resolve, her sense of identity or the foundation of beliefs upon which she’s been raised.

Moreover, Rachel becomes oddly less strong as the film goes on, not more, and eventually relies on others to sort of rescue her from a life that she isn’t sure she wants. Worse, the script assembles a group of supporting characters that are important to her life, but who turn up primarily because the script demands them to, and not because of anything plausible – unless “heaven-sent” is a justification.

And then Rachel’s rescuers provide the story with a deeply conventional payoff, becoming a sort of unconventional “family unit” and rule-free support system for a character who quite honestly needs to have someone explain a great many things to her. That Clyde and the others immediately fall in love with Rachel feels more like a testament to Garner’s performance than a sense of measured, believable storytelling.

Again, however, many of the performances are great, and the basic ideas are solid, even if Thomas doesn’t quite have the maturity to keep the reins tight on either actorly self-indulgence or narrative naturalism. (Culkin is solidly sympathetic as a doofy ne’er-do-well, but the dramatic repercussions of his immediate affection for Rachel make little sense and are never sufficiently explained.) But as Thomas’ writing and directing debut, “Electrick Children” exudes raw talent and heralds the arrival of a voice that could evolve into something truly special, even if it’s currently a little unsure of what exactly it wants to say.

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