Director Crystal Moselle is sitting in the conference room at the roomy, exposed-brick office of Magnolia Films in Chelsea. Pointing at a pile of half-empty take-out containers on a side table, she asks for them not to be thrown out because “I’m sure the boys will want to take the food home.” It’s a gesture that reveals the closeness between Moselle and the Angulo brothers, the subjects of her remarkable debut documentary The Wolfpack. The brothers (who are in the office that day for press photographs) didn’t get to finish their food—but Moselle has their backs.

The story of a hyper-isolated family in one of the world’s most populous cities, The Wolfpack is the result of a chance encounter. In 2010, Moselle was standing on First Avenue in New York’s East Village when a teenage boy ran past her, his long black hair billowing behind him. He was followed by five more boys, all with streaming black hair, and Moselle’s instincts kicked in: she chased after them and asked where they were from. When the boys heard she was a filmmaker, they were thrilled—they wanted to get into filmmaking too, they said.

So began a friendship that, as it progressed, allowed Moselle to uncover the boys’ strange story. Raised on the Lower East Side, the six of them and their mentally disabled sister were kept under lock and key by their father, Oscar, a Peruvian drifter who regarded himself as the god of his own tribe, and who gave the children Sanskrit names like Bhagavan, Govinda, Mukunda, and Krishna.