In a pew toward the rear of Grace Church, in Greenwich Village, in the midst of a weeklong New York City snowstorm, Russell Brand is at peace. The recovering drug/sex/fame-addicted rocker of a comedian—best known in the United States as recovering drug/sex/fame-addicted rocker Aldous Snow in Forgetting Sarah Marshall and Get Him to the Greek—is almost unrecognizable: clean-shaven, hair a shoulder-length Byronesque curl. Granted, we're in a church, and Brand, now an avid Transcendental Meditation practitioner, is also in character: It's the last days of reshoots for his remake of the Dudley Moore classic Arthur, and the crew is assembling for the afternoon scene—the chastened billionaire alcoholic's six-months-sober "share" at a 12-step meeting.

For a man whose life and career could be summed up in three words—LOOK AT ME!—Brand seems uninterested in sharing this moment. In the vaulted, candlelit nave, his gaze on the sacristy, the long, lean Essex-born actor might be taken for a parishioner seeking a private moment with his God amid the day's tumult and temptations.

Or not. When our chat turns from Arthur to Dudley Moore to Peter Cook—who, being a self-destructive prodigy, is the member of that famous comedy duo one would far more quickly associate with Brand—it's clear this moment is neither passing nor private. Arthur opens this month, as does the animated film Hop, in which Brand voices the Easter Bunny; Brand has also been at work on an Oliver Stone-produced documentary on happiness, and he's hosting Saturday Night Live the following weekend.

"Dudley was adored, and after Arthur—I'm being careful here—in a mainstream way," he says. "He flourished outside the partnership, whereas Peter didn't, a measure of the incredible personal warmth that Dudley brought, a more useful commodity—put repulsively bluntly—and required to become a successful movie star, which is something I've yet to do."

Welcome to the imponderable mystery of Russell Brand, a man who contains multitudes. Variously infantile and too brilliant for the half-dozen media he's mastered (both of his memoirs, My Booky Wook and My Booky Wook 2, were best sellers), he's been shape-shifting for years. Comics don't release locusts on their audience, mutilate themselves (or pigs' heads), and stick Barbie dolls up their ass on stage. TV hosts don't take baths with homeless junkies, jerk off men in public restrooms, or cover antiglobalization marches naked. Nor do they come to work on September 12, 2001, dressed as Osama bin Laden, accompanied by their drug dealer (and his 8-year-old son), and proceed (with pusher pére et fils) to the handicapped toilet to smoke crack.

Multitudinousness is useful in marriage, particularly the one between this unique and driven man and his equally unique and driven wife, pop star Katy Perry (a union Brand describes as "at once the most mundane and spectacular thing in the world"). In tandem with his remorseless self-honesty, the trait is a huge part of Brand's act, his allure, and his imponderability.

He's hoping to soften all of the above with Arthur, but Brand has made himself a tough act to follow. His AA "share" for the cameras today is intended for a montage—neither he nor his character is meant to be funny, but they are. And Brand, who freestyled Shakespeare as the jester Trinculo in Julie Taymor's The Tempest, clearly can't help but improvise. The takes career wildly and hilariously as Brand warms up, but each ends with the same note of tragic-hopeful sobriety as Arthur/Russell incants: "One day at a time." Eight years clean and sober, Brand, who still attends meetings three times a week, nails that convivial poignancy every time.

"I suppose that's what this film is about," he says as his ever-present entourage assembles around him: manager, personal assistant, makeup, wardrobe, sponsor, driver, a six-foot-nine mountain of a security guy in a leather coat named Big Danny—whose second job seems to be telling Brand to "fuck off" when he gets too New Age-y. Brand is an addict and his entourage the flesh and blood of his Program. "And I am making a real effort to be convivial," he says. "God help us all if I can't convey that in this bloody church."

His gaze turns to the sacristy. "We'd always known I'd end up in the pulpit"—his voice warbling up to a dialect from some obscure English district. This brings out homesickness in his entourage, almost all of whom are English, many from Essex, and I'm soon engulfed in unrecognizable allusions and jokes and incomprehensible sentences.

It shouldn't play in Peoria. Both Brand and his accidentally-on-purpose rocker persona are untranslatable, broken English. Yet everything he's tried has bridged the pond, even his failures. Like hosting the 2008 Video Music Awards, whence quips on the Jonas Brothers' virginity and George W. Bush's IQ earned him death threats and a No. 5 perch on Google's top searches.

When he arrived for his first U.S. audition, for Sarah Marshall, jaws dropped. Aldous Snow was initially written as a proper English chap, a writer. "We were convinced the casting director had played a gag on us," says director Nicholas Stoller. "The hair, makeup, clothes—I think he had 18 belts on? Jason [Segel, the film's star and screenwriter] asked Brand about the role, and he said he'd 'had a cursory glahnce'—what a thing to say to a director and writer. Asked about improv, it was as if he'd never heard of that either. Then he started in. When he left, Jason got up and did a jig." The part was rewritten.

Brand can elicit physical reactions like that. Kate Moss, whose conquest helped cast him as England's master cocksman, reportedly squealed when she first saw him, on a British talk show. Perry, introduced to Brand for her cameo in Get Him to the Greek (later cut), remembers bunny-hopping away from their onscreen kiss. If they'd met a few years earlier, the famously straight-edge Perry would doubtless have had a different visceral reaction.

My Booky Wook is an alarmingly frank account of Brand's early life: abandonment by his father, his mother's three bouts with cancer, binge eating, bulimia, depression, death obsession, self-harm, leaving home at 16, then drugs and two diagnoses of bipolar disorder—with a great deal of evidentiary behavior between. Among the scars on his arms and torso are some nasty ones from a party for incoming drama students. Brand welcomed them by smashing his vodka glass on his head, then using the shards to gouge his torso and rake his arms till they bled.