Judging from Martha Marcy May Marlene, one of the most talked-about feature films currently showing at the New York Film festival, relative newcomers writer/director Sean Durkin and actress Elizabeth Olsen (younger sister of Mary-Kate and Ashley) were born with the right gene. This new thriller is so tight and poised that it appears to be the work of long-collaborating veterans (it may prove difficult for them to live up to this standard through the rest of their careers but that’s a good problem for them–and us–to have to face).

The film, which nabbed a Best Director award at Sundance earlier this year, follows Olsen’s character, Martha, after she escapes from a cult in upstate New York and is taken in by her sister Lucy (Sarah Paulson) and brother-in-law Ted (Hugh Dancy) at their ritzy summer home in Connecticut. As she tries to reintegrate herself into normal life Martha is continually troubled by recollections from her time in the cult; often she cannot distinguish memory from reality, and it’s similarly difficult for the viewer to be exactly sure whether a given scene is a dream, flashback or what passes for reality.

This creates a notable amount of tension, both for the audience and between Martha and her sister. Lucy is constantly trying to find out what exactly happened to Martha, and why she behaves so abnormally (she seems to have forgotten her table manners, strips naked without warning, and sits on the couple’s bed while they’re having sex). Martha is so overwhelmed by her experience and her fear that the cult members will come after her that she can’t even tell Lucy where she’s been for the past two years—she doesn’t really know herself.

The scenes of life in the cult are fascinating and mostly understated; there’s very little bloodletting and grandstanding, but we are shown scenes that detail the cult’s brainwashing strategies , which include renaming, food restriction and communal sex (at the post-screening press conference, Durkin made a point of discussing his research into cults, and the fact that all these activities were drawn directly from real accounts of recent cult life in the Northeast.) John Hawkes (“Winter’s Bone,” “Deadwood”) plays the Mansonesque leader, and the gaggle of other women who indoctrinate Martha (rechristened Marcy May) convey the everydayness of their bizarre living arrangement.

Later on, we see Marcy May reprising this caretaker role with another new cult member; her transformation within the flashback sequences from ingenue to leader is a little scary, as she’s clearly taken the commune’s brainwashing to heart. However, her transformation back to Martha after she’s escaped is even more striking. She’s now world-weary enough to be cynical and cruel (she lectures Lucy and Ted on their materialistic lifestyle), but still a damaged teenager on the inside, capable at any moment of falling into debilitating hysterics.

Olsen’s performance is excellent, and the accolades she’s being showered with are well deserved. Far from the self-absorbed performance style one could logically expect from someone with her celebrity upbringing, Olsen instead manages to be both damaged and pragmatic, mysterious yet ordinary. Her turn as Martha isn’t a put-on; it’s as genuine a piece of acting as anything you’ll see this year (or, at least, anything that I’ve seen so far).

“Martha Marcy May Marlene” will open in limited release on Oct 21st (watch the TRAILER for Martha Marcy May Marlene and many other upcoming releases here)