She has the glow of someone who knows something we don't, a Buddha's smile, and a couple of lugs who will escort you from the premises if you dare doubt her.

She is Maggie, a mystery woman who claims to be from the future - 2054, to be exact - and who hides out in a basement in California's San Gabriel Valley, where new devotees are brought, blindfolded, thoroughly scrubbed down, and dressed only in hospital gowns, to sit at her feet.

Yes, it's a cult movie - that is, a movie about a cult. In Sound of My Voice, directed by Zal Batmanglij and cowritten by Batmanglij with his star, the eerily good Brit Marling, people give up their ideas and identity to follow a charismatic diviner who may or may not be for real. Groupthink, Jonestown, this could all turn bad.

An economical thriller, both narratively and budgetarily, Sound of My Voice serves up moments of extreme dread and discomfort, but works a winning undercurrent of playful absurdity into the material as well. (To wit: the provenance of a secret handshake, and a strange gag about the '90s Irish pop band the Cranberries.)

The audience is brought into this weird, clandestine world via Peter and Lorna (Christopher Denham and Nicole Vicius), a couple who claim to be newbie disciples, carefully vetted before they're allowed to bask in Maggie's presence. In fact, he's a journalist intent on exposing the sham, and Lorna is his partner. Needless to say, their covert operation puts them both in danger - not to mention putting serious strains on their relationship.

Sound of My Voice reminded me, in its creepy calm and its minimalist production values, of The Man Who Fell to Earth, the enigmatic 1976 David Bowie stranger-in-a-strange-land thriller. There's a documentary-like realism at work here (and at play), and Marling, projecting an aura of unpredictability and vulnerability - but also ferocious certainty - has no trouble inhabiting the role of this self-professed time-traveler, ready to save her believers from the apocalypse she knows is coming.

Because, of course, she has already been there.

Sound of My Voice *** (out of four stars)

Directed by Zal Batmanglij. With Brit Marling, Christopher Denham, Nicole Vicius, and Davenia McFadden. Distributed by Fox Searchlight.

Running time: 1 hour, 25 mins.

Parent's guide: R (nudity, profanity, violence, adult themes)

Playing at: Ritz Five and Rave Motion Pictures at the Ritz Center/Voorhees.EndText