Batmanglij, whose brother Rostam is a member of the band Vampire Weekend and has contributed music to his films, said he was similarly struck by Marling when the two of them and Cahill were Georgetown undergraduates together.
"When I first met her, she had this quality, this luminosity and kindness, qualities that I think are a version of star power," he said. "She had it. That is so rare. I'd never encountered someone like that before, so I just wanted to see her on screen."
Marling co-directed a documentary with Cahill that explored Cuba-U.S. relations, "Boxers and Ballerinas" (2004), and she starred in Batmanglij's short "The Recordists" (2007) before making features with both filmmakers, including another upcoming one from Cahill.
Inside AMC's River East multiplex, where Batmanglij and Marling conducted a Q&A after a screening of "The East," the director pointed to a mural portrait of a young Ingrid Bergman and said, "Brit has that quality."
Marling now lives in Los Angeles, but she said she still considers her Chicago-area years to have been formative. "Every time I see Lake Michigan, I feel some sort of thing," she said. "It feels like a homecoming to me, the colors of it, the sea glass that I used to collect on the beach that I still have. It's always nice to come back here, because I don't really feel like I have roots anyplace else."
She has particularly fond memories of visiting the Museum of Contemporary Art and walking to the lake to contemplate what she'd seen, which often were works by the late Henry Darger.
"He's my favorite, because he's an outsider," she said. "I love outsider art. I love when somebody's making something without the awareness of being seen or the work being loved or not loved. He was just doing that because he had to do it" — she laughed that tickle of a laugh — "to survive."
Marling has some outsider-insider tension going on herself. After breaking into the industry by writing her own independent ticket, she's now increasingly in demand as an actress (she also played the Richard Gere character's daughter in last year's "Arbitrage") while being represented by the heavy-hitting Creative Artists Agency.
So does she keep writing her own screenplays at a time she openly laments the paucity of great starring roles for women, or does she concentrate more on moving forward as a performer?
"I'm working really hard at trying to become a better writer, but I don't know that I'm maybe capable of writing the things that I could achieve as an actor," she said. "The thing about acting that's so provocative and intense is that you're walking in someone else's imagined landscape. It's like a foreign country that you enter. There's something hard to do about that and something that can be sort of transcendent about it."
Although he and Marling have been kicking around ideas for another screenplay, Batmanglij said he looks forward to seeing what happens "when she works with really great directors and gets out of the kiddie pool with us. She hasn't turned it on fully yet. I'm so curious and excited for when that happens."