Elizabeth Olsen gives a thoughtful and quietly powerful performance as Martha, a troubled soul adrift, trying to find her place in the world. Craving acceptance and understanding - and, underneath, help - but never finding it.

The film constantly inter-cuts back and forth from her seeking refuge from straight society by joining a cultish commune, and trying to reconnect with her sister after fleeing the cult. The fractured way of telling the story, along with the hazy vibe many of the scenes had, was a good way of representing Martha's psychological fugue state.
A good companion piece for Martha Marcy May Marlene would be Lars von Trier's sublime Melancholia. Both feature a distressed, paranoid young woman being helped by a sister who is herself emotionally ill equipped to provide adequate help, and who also has a husband who is a complete arse.
It amazed me how the sister, Lucy (a brittle Sarah Paulson), didn't cotton on to the fact that, from the moment Martha calls her up after being missing for two years, and clearly traumatised, something was clearly deeply, deeply wrong. She never really tries to get to the bottom of what Martha may have been through, nor seeks professional help soon enough.

Hugh Dancy as the husband, an uptight Brit called Ted (note to Yanks: Brits aren't often named Ted, just fyi), was a little too over-drawn and cliched. Like Melancholia this is a film peopled by flaky, emotional women, and cold, dispassionate man. One of the best scenes with Dancy and Olson was them both taking his boat out onto the lake and having the only 'real' conversation the two of them have; Martha's mocking laughter at his plans was wonderful.

Like much of the movie, details about the cult commune were kept vague. Which was a good move, I thought, although the cult's inevitable slide into being a kind of Manson family was a cheap and unnecessary way of giving Martha a reason to come to her senses. But, still, Patrick the cult leader (John Hawkes) was just the right amount of both charismatic and controlling. He rapes you, then he sings to you a Jackson C. Frank song, the little charmer.

Ambiguous endings can be frustrating, but it made perfect sense here, and it fitted completely with the equally ambiguous scenes that immediately preceded it. The story is told entirely from Martha's (unreliable) perspective, and the more fearful and delusional she becomes, so does the film. The ending wasn't the film being vague this time, it was Martha.