Jonah Hill, Marisa Tomei, and John C. Reilly in Cyrus
Jonah Hill, Marisa Tomei, and John C. Reilly in Cyrus
Cyrus, a low-budget comedy that's already been a hit at a dozen prestigious film fests this year, is entering the crowded summer-movie field this week, and it may prove to be a surprising winner at the box office.

Directed by brothers Jay and Mark Duplass, the film tells the story of John, a divorced middle aged man-child (played by Oscar and Tony Award nominee John C. Reilly), who can't believe his good fortune when he attracts the attention of the beautiful Tina (played by Oscar winner and stage veteran Marisa Tomei). All goes well until he meets her 21-year old son, Cyrus (Jonah Hill), and discovers their symbiotic relationship. Questions abound, most of which John brings to his long-suffering former wife and best friend, Jamie (Catherine Keener), on the eve of her remarriage.

Having come from the world of true indie films, the Duplass brothers -- best known for their cult favorites Baghead and The Puffy Chair -- weren't sure about working in a more traditional system. "We were nervous about making our first studio film," says Jay. "We'd heard horror stories and we needed to lay the groundwork so we could maintain the integrity of the way we shoot." Indeed, as Mark explains, their process includes a lot of improvisation on the set: "We write a script in order to create a structure so we can scrap the script and then wait for something really magical and special to happen," he says.

Still, there was a script, and it was written with Reilly in mind. "I'd never had a script actually written for me before," admits Reilly. "And then when we actually met, they told me, 'If you don't do this film, we'll do something else!' It's not everyday you hear directors say something like that or that you get a chance to shoot a movie in order from first scene to last. And then to their credit, they actually threw the script out and said, 'if stuff happens that's great,' which is actually kind of scary. It's a lot easier to just memorize a script and then do your best with the lines."

John C. Reilly and Jonah Hill in Cyrus
John C. Reilly and Jonah Hill in Cyrus
And how do you research for an improvised script? "Mostly you have to be prepared to be unprepared, because there's no rehearsal. The whole story could change and they're shooting everything you say and do," he says. "But I've been lucky to work with other directors who encouraged some improvisation, such as Woody Allen, Paul Thomas Anderson, and Robert Altman; it's just never been before where the script is basically just a floor plan. And I really loved it!"

Tomei, who looks at least a decade younger than her mid-forties, had no qualms about playing the mother of a 21-year-old son once she saw the script. "I choose my roles based on what I respond to; every movie is different and you just go with the flow," she says. "I had never met either Jonah or John before, so I really appreciated the luxury of shooting in order. By starting at the beginning we could build the relationships. And I don't think we could have achieved the same kind of emotional truth that we did, because we didn't rehearse at all."

The actress is a new director herself; she recently shot the short narrative film Half the Sky, which deals with the exploitation of women. And working on Cyrus gave her a new perspective. "I really like the way they split up the work," she says. "Jay is his own cameraman while Mark follows the actors on a monitor and then they'll confer. Their collective way of working reminds me of my time with [New York theater company] Naked Angels. In fact, I've actually watched Cyrus twice now, once at Sundance and once at BAM. I never watch my films, so you have to figure that I really liked working this way. Now, I can't wait to direct my first full-length feature film!"