When Kevin Spacey was pitching Beyond the Sea — his biopic about '50s pop idol Bobby Darin, which opens tomorrow — the big Hollywood studios all asked him the same question: "Who's heard of Bobby Darin?" As it turns out, Spacey's costar in the film, Kate Bosworth, had the same reaction when she first met with Spacey to discuss the project.

"He told me, 'I'm doing this movie about Bobby Darin and Sandra Dee,'" the 21-year-old actress remembers. "I was like, 'Sandra Dee from Grease? You're making a remake of Grease?' He said no and then drew me into their story."

Despite her lack of firsthand knowledge about yesteryear's teen heartthrobs — and the fact that Dee is mentioned in a Grease song but wasn't actually in the movie — Bosworth was Spacey's first choice for the part. That's largely because, he says, of her "mature face." According to Spacey, her grown-up look helped overcome the obvious age difference between the two.

"[With Kate,] I knew it wasn't going to be an American Beauty scenario," Spacey laughs. For her part, Bosworth wasn't bothered by the generation gap either. "I felt incredibly safe because he knew everything about Bobby Darin," she says. "I've never worked with such a seasoned actor before as a director. He has this great sensitivity in working with another actor, and I never felt jarred by the switch from director to actor."

Next up for Bosworth is a small roll in an indie film called Bee Season with Richard Gere and Chocolat's Juliette Binoche. "It's about a family that is coming into their own spirituality," she says. "I play a Hare Krishna devotee who befriends the son and helps him figure out his own spirituality."

Bosworth's also weighing the idea of entering the world of higher education at Princeton University (which had previously accepted her as a student). "I definitely want to go back to school someday," she says. "For me, it's about when I feel really ready to go. Princeton has been very cool about letting me decide when I want to attend."