Here’s something I never thought I’d write: One of the best films of the year is the debut of a 29-year-old writer-director that stars the younger sister of the Olsen twins. But watch “Martha Marcy May Marlene” and try not to be swept up in its dark, disconcerting world, one in which even the pristine home of a beloved family member can be uncomfortable, even terrifying. Its first few minutes are nearly silent. We watch a typical day at a small farm in the Catskill Mountains, its residents going about their business with unthinking purpose.

There’s plenty for us to think about, however. Why do the men and boys eat their dinner before the girls, who peek in the room with one eye, ready to move as soon as it’s their turn? Why are some of the women dressed like Amish mothers, while others wear provocative cutoff jeans? And why does one of those young women tiptoe quietly out of the house early one morning, breaking into a run as soon as she’s reached the forest that lies just beyond it?