Joseph Fiennes is not your run-of-the-mill heartthrob: He's not buff. He's not finely featured. He's not particularly animated; in fact, he usually speaks in a voice just above a whisper. And he's spent a good part of his career wearing a doublet, wide pantaloons and tights - not the most flattering of costumes. But Fiennes, who can recite Shakespearean sonnets on command, is intelligent, elegant and, when he allows himself, charming. "How can you be a heartthrob in tights?" he asks, shifting in his chair at the Parker Meridian Hotel and looking rather uncomfortable in a trendy gray suit with pink stripes and a bubblegum-colored shirt. "It's difficult." Then, remembering the oversize knickers he wore in his last two films, he adds, "I think we're going to bring back the big-ass pants."

The 28-year-old is vastly more comfortable in big-ass pantaloons than in the high-fashion suit he's been lent for today's photo shoot - perhaps because he's spent much of the past few years working in period costume. During his tenure with the Royal Shakespeare Company, Fiennes won raves for his performances in Troilus and Cressida and The Herbal Bed (a play about William Shakespeare's daughter), but he left the RSC just as the troupe offered him the role of Romeo. "I don't find Romeo that appealing - he's a bit of a mooning lover," says Fiennes. "And I'd done two years at Stratford and London. It's tough, and it's important to get out for a bit."

It didn't hurt that he was beginning to land parts in films such as Stealing Beauty and Martha - Meet Frank, Daniel and Laurence, a British film to be released in the U.S. this spring. These roles led to Elizabeth and to the new romantic comedy Shakespeare in Love, in which he plays the Bard himself. Directed by John Madden (who helmed last year's Mrs. Brown), Shakespeare follows young Will Shakespeare though a bout of writer's block, amorous misadventures and the first performance of, ironically, Romeo and Juliet.

"Joseph's character is surrounded by banana skins throughout the movie," says Madden. "But he took the role seriously and was not threatened by the comedy or the absurdity that the guy's in. Some other actors I met were desperately concerned about that - but not Joe."

Fiennes's low-key humor and seriousness - along with fine performances by Gwyneth Paltrow, Geoffrey Rush and Judi Dench - anchor Shakespeare's frothy historical romance. Conceived by Marc Norman, the screenplay owes much to Tom Stoppard, the acclaimed British playwright behind Arcadia and The Invention of Love, who was brought in to take a pass at the script. "Stoppard's writing - with its one-liners, academic twists and plays on words - is a joy and a bit of a gift for any actor," says Fiennes.

The actor actually bumped into Stoppard at a London bookstore before shooting began. "He was buying all these amazing books, and I was green with envy," he says. "He was really very sweet, though." Stoppard remembers the incident differently: "This story reflects no credit on me. This young man came up, and I thought he was [Madden's] assistant." Once Stoppard figured out that this was his Shakespeare, he invited the actor back to his home and lent him several books for research. During the long search to fill the role, recalls Stoppard, "the one thing we came back to was that if you didn't believe this person wrote the plays, then we were sunk. That was perhaps the main thing about Joe. You look into his face, and you feel there is somebody who could have done it. He's got an artist's face and build - and a very macho center."

Some critics have commented on Fiennes's physical presence, calling him a "heart-melting new man" and a "sensual beauty." When discussing his press, Fiennes says, "So much of it is fast-food talk." He's certainly witnessed the drawbacks of sudden celebrity - in particular, the media coverage of his brother Ralph's life. (After Ralph left his wife, ER's Alex Kingston, for actress Francesca Annis, he was dissected in all the British tabloids.) When it does come to fame, the younger brother speaks hypothetically, as if the possibility of a stranger asking where he buys his underpants is still a long way off. But stardom may be closer than he thinks. "During Shakespeare in Love, he was looking at me with these terrible [costume] teeth," says Geoffrey Rush, Fiennes's co-star in both Elizabeth and the new film. "And I'm watching him, thinking, You're eating this role alive - rolling on the floor, wielding a sword and leaping balustrades. This guy is Errol Flynn; he's Cary Grant; he's everybody!"

He is not, however, Arnold Schwarzenegger. "I don't think I could survive an action picture," says Fiennes, grinning. "The Shakespearean classics didn't give me enough training." Instead, he'll spend time between movie gigs on the stage, where he feels most comfortable. "There are fewer interruptions - once the actors are on the stage, they tell the story," he says. "And I love the idea that people can sit and look anywhere they want. They're their own directors."

Unlike many actors, Fiennes claims he has no interest in directing either plays or films. "How could I play God?" he asks dismissively. Well, he did play Jesus Christ in Dennis Potter's Son of Man, to much acclaim. "Yes, but he got nailed in the end," says Fiennes, with a tiny smile. "It's a crucifying job, from what I've seen." He speaks from experience; Two of Fiennes's six siblings are directors. His older sister Martha just finished directing a movie version of Onegin, which stars brother Ralph.

When asked about the inevitable comparisons to his older brother, Fiennes pauses. He explains that he doesn't mind talking about his relatives, but the knowledge that they might not want to be talked about makes him more circumspect than usual - which is to say, almost mute. What Fiennes likes to discuss is his work, including the upcoming Rancid Aluminum, an independent film currently in production in Ireland. After that wraps, he hopes to come to New York and Miami in February to shoot Paul Schrader's film Forever Mine. In the meantime, Fiennes is using the few days of the Shakespeare junket to grab Christmas presents at Barneys ("or maybe I'll just buy the bags and fill them with secondhand gear") and to brush up on his American accent. "I jump into cabs and listen to the guys," he says. "I sort of mumble behind them, copying what they're saying to see if I can do it." How well does he succeed? "I fail miserably," he says with a grin.