The former Wu-Tang Clan member talks about working with Quentin Tarantino, composing film soundtracks, and the death of ODB

Like a hip-hop Clark Kent, the RZA walks quietly through the world. The mastermind behind the raucous Wu-Tang Clan, one of the biggest and best rap acts of the ’90s, doesn’t wear diamonds in his ears or around his neck. He’s shy and thoughtful, and he talks like he has gumballs in his mouth, words rolling out without the letter r. (”Jim Cawwey was widiculous in Bwuce Almighty, wight?”) He hides behind bookish Polo frames that his sharp eyes don’t need. ”These are just part of my disguise,” he says with a sly chuckle. You may not always notice the RZA, but that’s just part of his plan. The rapper who once reigned supreme switched identities while nobody was watching.

Noodly limbs curled into the corner booth of a Manhattan restaurant, where he’ll linger through a shift change and a sunset, the RZA (born Robert Diggs) approaches the lunch menu like he’s coming up with a battle strategy. This takes a while because he doesn’t touch white sugar or caffeine or meat. After settling on peppermint tea and bean soup (”Start off light,” he advises), the RZA leans in close and softly explains that hip-hop was just a hobby and he has greater things in store for the world. The crazy thing is, you kind of believe him.

When superstars fade, they have a tendency to cling desperately to their dulled fame. But here is a better story, the tale of a man who found a way to skirt the indignities of irrelevance. When Wu-Tang’s record sales started to droop with 2000’s The W, the RZA (pronounced ”RIZ-uh”), an untrained musician, crafted a meticulous plan to transform himself into a serious film composer. Now, riding Grammy nominations for the music in Kill Bill — Vol. 1 and 2, the RZA’s distinctive sound helps set the tone for the new Jet Li movie Unleashed and the May 19 Quentin Tarantino-directed CSI finale.

Mission accomplished, the RZA is ready to move on to an even greater challenge. With roles in Jim Jarmusch’s Coffee and Cigarettes (2004) and in the Jennifer Aniston thriller Derailed (due in theaters this fall), he wants to break into acting and eventually directing. Understand, though, that this is not a casual lark, a crass move to join the ranks of rappers who continue to find second acts in Hollywood. ”If all of a sudden I walk out like, Yo, I’m an actor! I’m a director! Nah man, it takes training to do that. And I won’t disrespect hundreds of years of other people’s work, because I don’t like how hip-hop has been disrespected by fake rappers coming in making their money.” Instead, the RZA’s armed himself with A-list mentors like Tarantino and Jarmusch, and he’s walking around with a copy of an Alfred Hitchcock biography in his bag. ”I keep telling him, we need you as a director as well as a musician, producer, philosopher, all the other things you do,” says Jarmusch. ”RZA’s got a bigger plan than ‘It’s all about me and how much bling I have.”’

Is there anything the RZA can’t do? There is one thing, the worst thing. He couldn’t save his troubled second cousin, Wu-Tang’s Ol’ Dirty Bastard, who died last fall. And the RZA still can’t forgive himself for this one failure.