Elizabeth Olsen plays Martha, a former cult member who attempts to return to society and her sister (Sarah Paulson) in “Martha Marcy May Marlene.”

For someone who has presumably spent her life in the shadow of superstar sisters, Elizabeth Olsen—the younger sibling of twins Mary-Kate and Ashley—seems right at home in the spotlight. Playing a paranoid and skittish escapee of an abusive cult, Olsen exquisitely embodies the many names she carries in Sean Durkin’s first feature length film “Martha Marcy May Marlene.” As writer-director Durkin slowly reveals small pieces of the muddled puzzle that is the main character’s past, it is Olsen who expresses how damaged she truly is by those experiences. With her hollow, unsettling eyes and utter lack of social graces, Olsen makes the effects of brainwashing believable and genuinely frightening, and consistently keeps the audience as disturbed as her character.

The film opens with Olsen creeping through a large farmhouse. She passes rooms filled with sleeping bodies and stuffs a small backpack along her way. When she reaches the door, she takes off, fleeing into the woods across the street as someone calls out “Marcy! Marcy May!” She calls her sister Lucy (Sarah Paulson), who comes to collect her. Lucy calls her “Martha” and tells her she shouldn’t have disappeared for two years. Lucy brings Martha back to the summer home she shares with her new husband Ted (Hugh Dancy), where it becomes increasingly apparent that Martha has forgotten how to function in normal society.

As Martha continues her odd practices of wearing dirty, bland clothing, refusing to eat, and asking impertinent questions about her sister’s comfortable lifestyle, her present begins to trigger memories of her past, and chunks of her life in the cult she left are revealed. It turns out that she and her boyfriend Watts (Brady Corbet) first came to the cult in what was intended to be a temporary stay to try their hand at farm life. In flashback, they are introduced to the cult’s patriarchal leader Patrick (John Hawkes), who insists that they will “find their place” and that they simply “have to trust us.” With a slight frame and timid smile, Patrick seems benign enough. He takes an interest in the then-charming and polite Martha, renaming her “Marcy May.”

Though it is clear that Martha is wary of the cult, her vulnerability wins out and gradually she joins in, and the audience sympathizes with her need for stability. We see how Patrick subtly takes advantage of Martha’s insecurities, telling her that while her mom is dead, her father has abandoned her and her sister has gone off to college, her new “family” is here for her.

It is Olsen who carries this movie, seamlessly integrating the various facets of her character’s diffracted personality into a tense whole. While Durkin’s script juxtaposes the former Martha entering the cult with the current Marcy May on the run, it is Olsen who actually exhibits how drastic this transformation truly is. Martha’s polite nature dissipates as she is told to open herself up and join the family to become Marcy May. And when the cult takes a disturbingly violent turn, her snap back to reality is just as tangible. Olsen’s powerful and poignant performance conveys the deep-seated fear that the cult will recapture her, and ensures that Martha is sympathetic even in her most alienating moments.

Adding to the tense nature of Martha’s past is the misleading and charismatic Hawkes. Acclaimed for his turn as meth dealer Teardrop in the Oscar-nominated “Winter’s Bone,” Hawkes’s Patrick draws upon his rural upbringing to mask his manipulations with homespun wisdom. His repetition of phrases such as “trust us” and “share yourself” are almost hypnotic, easily absorbed into the subconscious.

Durkin employs a few choice techniques that add to the film’s pervasive tension. At moments of high stress, the film’s soundtrack features a low rumbling noise that can only be likened to blood rushing to the ears. The sound is viscerally effective, not immediately obvious in its implications yet slowly triggering a discomforting anxiety. There are also small tricks of the camera designed to draw out the film’s suspense, as in one scene where the frame seems to inch toward the shadow of a man before pivoting to reveal a woman rounding the corner.

But perhaps most affecting is Durkin’s emphasis on life cycles, both harmless and destructive, and the dangers of their banality. In this way, Durkin lends a sinister undercurrent to otherwise unassuming occurrences. Many of Martha’s daily meals are depicted—both the quiet, ritualistic ones with the cult and the often explosive ones shared with Lucy and Ted that grow increasingly uncomfortable as Martha’s strange behavior fails to improve. But most off-putting is the cycle of members joining the cult. Just as Martha was brainwashed, so she brainwashes young, impressionable newcomers and rationalizes away their fears with the same ease as Patrick, and repeating the same phrases.

Durkin’s and Olsen’s debut is a haunting glimpse into the rhythmic and mesmerizing functioning of a cult and what happens when that rhythm is abruptly broken for one member. Though the film’s ending may leave many unsatisfied and relieve little of the story’s tension, this seems to be Durkin’s intention: to ask if a cult ever truly leaves you once you’ve entered it.

—Staff writer Lauren B. Paul can be reached at lbpaul@college.harvard.edu.