A lot of buzz is surrounding a little horror film that uses a single camera shot to follow a wide-eyed, terrified girl around an abandoned summer house.

“It’s called ‘Silent House’,” but the film’s even bigger buzz is around the actress who plays that terrified girl – Elizabeth Olsen – and she is quickly turning into Sundance’s breakout star.

Olsen is a 21-year-old senior at NYU’s Film School and the younger sister of Ashley and Mary Kate.

Lizzie Olsen has two films at Sundance. She is also in another psychological thriller called “Martha Macy May Marlene,” and is getting major attention for both of them.

Olsen is in every shot of ‘Silent House,’ since the camera follows her in a single shot throughout the movie, either behind her shoulder or in front of her, capturing the rising fear, then panic then hysteria that she effectively sustains through the film’s 90 minutes. Something about her candor and affect are winning comparisons to Maggie Gyllenhaal, rather than her sisters.

So why haven’t we seen her before? The petite, green-eyed actress smiled shyly when we talked to her just outside a screening of “Silent House.”

 “I have acted, but at school, training, and reportories,” she said. “I started auditioning a year ago. “ (Pictured after screening at right with actors Eric Sheffer Stevens and Haley Murphy)

She added: “Everyone in my family is very different from each other, and support one another’s choices.”

It seems that Olsen didn’t really want the path of her more famous twin sisters, who’ve been in the public spotlight since they were babies and on “Full House.” (Ok, am I the only one who finds it funny that Olsen’s first film to be seen is “Silent House”?)

Filmmakers Chris Kentis and Laura Lau - who shot the single camera thriller "Open Water" a few years back -  shot “Silent House” in 5 weeks in New Rochelle, based on a Uruguayan movie of the same name. It was technically very challenging, since every shot was long and involved a long list of production staff and actors working together and correctly to maintain the shot.

That, and the intensity of the role, made it incredibly gruelling for Olsen, she said.

“By the end of the day you’d have given all you can every time – it was exhausting,” she said. “I had lots and lots of migraines and sinus infections from breathing in snot. It was just really exhausting.”

Meanwhile, ‘Martha Macy’ was also not a minor effort either. It tells the story of a young woman rapidly unraveling amidst her attempt to reclaim a normal life.  She escapes a cult member in rural New York, and Martha and seeks help from her estranged older sister Lucy (Sarah Paulson), though she is unable and unwilling to reveal the truth about her disappearance. With a mounting sense of dread, Lucy comes to realize that her sister’s bizarre behavior may point to something much graver than an idiosyncratic personality.   

By the way, I asked Olsen why her sisters apparently haven’t helped her get into the movie business. She didn’t ask, she said. “If I asked them they would have,” she said.

“But I wanted to do it without asking for the favor.”