Martha Marcy May marlene, Elizabeth Olsen, John Hawkes

Elizabeth Olsen plays a young woman under the control of a cult leader (John Hawkes) in “Martha Marcy May Marlene.”

First, you give him your name. You tell him your name is Martha, and he smiles a friendly, crooked smile and tells you he thinks you look like a Marcy May. So from then on, your name is Marcy May.

First, you give him your name. And then you give him everything else.

"Martha Marcy May Marlene" is a brilliant, quietly unnerving film about a smart young woman (Elizabeth Olsen) who falls completely under the sway of a charismatic cult leader (John Hawkes). Even though the movie begins with Martha fleeing the cult compound, she finds that her mind isn't nearly as easy to reclaim.

In his first film, writer-director Sean Durkin effectively builds suspense out of seemingly empty space, using silence and off-center framing to slowly build tension. And this is a breakout performance for Olsen (the younger sister of Mary-Kate and Ashley) on the level of Jennifer Lawrence's in "Winter's Bone." Olsen makes Martha sympathetic and believable, even as she descends into a situation that most can't imagine.

The film opens with Martha on the run through the woods, her fellow disciples pursuing her. But they let her go, perhaps confident she'll come back on her own. Instead, Martha is able to call her estranged sister Lucy (Sarah Paulson) and find refuge with her and her yuppie husband (Hugh Dancy) at their summer house.

Martha doesn't tell her sister where she's been living for the past two years, but she's still haunted by the ordeal. As she stares into space, Durkin weaves in Martha's memories of the cult so seamlessly they don't feel like flashbacks; part of her still seems to be there.

Those memories chart Martha's gradual assimilation into the cult, how cult leader Patrick (Hawkes) played on her need for family and security. Patrick controls her with flattery and compassion, making eye contact and saying things like, "I worry for you" and, "Please don't be selfish."

It's another brilliant performance by Hawkes; while Patrick displays flashes of anger once or twice, he's much scarier when he's talking calmly and earnestly to Martha, his skinny arm around her shoulder. He doesn't have to tell Martha what to do; he makes her want to prove herself to him by doing it. By the time Martha realizes how depraved the cult is, it's too late, and before long, she's helping "guide" new recruits, too.

It's an insidious progression, made even more so because the cult's rural compound seems so bucolic and peaceful, and the other cult members seem so friendly. Contrast that against the IKEA-catalog perfection and brittle atmosphere of Lucy's life, and you can see the appeal to a lost soul like Martha.

In fact, if there's an off-note in "Martha," it's that Lucy and her husband are so shrill and unlikable, their parts so underwritten, that they seem to serve only as a representation of the shallow, materialistic life Martha rejected.

But that's a minor quibble, since Olsen holds our attention for every moment as a woman with a damaged psyche relearning what it means to be normal again. She's wounded, frightened, unexpectedly angry at times and feels alienated from the world.

Olsen shows us the contradicting emotions churning in Martha, suggesting each emotion subtly with a flick of her eyes or a twist of her mouth. Her deeply felt, haunting performance, and the movie, are very hard to shake.