SOUND OF MY VOICE has moments that make you want to cringe out of your skin with embarrassment. Like when a young couple is inducted into a super-secret cult and have to prove their devotion with a complicated handshake, the likes of which was last seen at Rydell High's prom. Apparently these two were born to hand jive, because this embarrassing rite is endlessly repeated during Sound of My Voice's scant 85 minutes. In spite of this—remarkably—the quiet, uneasy movie has some truly mesmerizing moments. Just don't expect much in the way of answers.

Peter, a young grade-school teacher (Christopher Denham) and his girlfriend, Lorna (Nicole Vicius), are bound and blindfolded en route to their first meeting with Maggie (Brit Marling), a charismatic leader of a white-clad, basement-dwelling cult in Los Angeles. Maggie maintains she's a time traveler from nearly 50 years in the future, but in this present, she's a sickly creature, holed up in an empty house, asking her devotees for blood donations and blind trust. Peter's there on a personal mission to prove Maggie's a fraud, documenting the sessions with a hidden camera in his eyeglasses, but he finds himself just as unwittingly devoted to Maggie as her most crazy-pants brainwashed followers.

Director Zal Batmanglij wrote the screenplay with Marling, and they do everything in their power to keep the audience guessing about every question the film asks: Is Maggie for real? What are Peter's real motives? Why is James Urbaniak shooting up a weird little girl with a mysterious substance? It all becomes very frustrating by the lightning-fast end, even as it engages through Marling's creepy and transfixing performance. But why on god's green earth do they keep doing that dumb hand jive?