Macaulay Culkin still has floppy blond hair, bright red lips and the pale, skinny body of a 12-year-old choirboy. I can tell because he's standing in front of me in his boxer shorts as he changes from a pair of stenciled Comme des Garçons bondage pants into his preferred plain black jeans following a Paper photo shoot. His passport and a packet of Marlboro Lights are lying on the coffee table. The 23-year-old actor carries the travel document with him everywhere he goes, since he does not have a driver's license and gets carded when he buys cigarettes or beer. In the public imagination, Macaulay Culkin is still the mischievous little imp he played in the Home Alone movies, a perennial prepubescent cherub, and certainly not old enough to do anything as adult as smoke or drink. But that may change with the release of the film Party Monster.

After dropping out of the movie business in the mid-'90s, and a bitter legal dispute with his father, who used to manage his career, the former child star has chosen for his comeback role the part of drug-addled club-kid-turned-killer Michael Alig. In 1996, the Limelight party promoter murdered his buddy Angel Melendez in an unspeakable manner -- his head was bashed in, his mouth filled with Drano, his limbs chopped off and the body dumped without ceremony into the Hudson River.

Sitting on a couch in a Chelsea studio, Culkin recalls the three years it took for him to agree to sign up for the part: "When I was first sent the script, I threw it in the garbage like I did with every other script I was sent at the time. I was basically retired." But after much badgering from Fenton Bailey and Randy Barbato, who co-directed the film, Culkin read the script, which is for the most part based on the hilariously campy book Disco Bloodbath, by Alig's friend James St. James (Simon & Schuster, 1999). Although he loved it, his handlers advised him to turn it down flat. "A lot of people around me were scared, and some said not to do it," he admits. So why did he take such a controversial role?

The obvious assumption would be that Culkin wanted to shatter the cute-as-a-button image that made him famous but which he now regards as an obstacle to his being taken seriously as an actor. Or it might have been another act of Oedipal rebellion against his controlling father, Kit Culkin, a nightmare stage parent and failed actor who tried to relive his dreams of success through his son. (He and Macaulay haven't spoken in years.)

But Culkin pooh-poohs this notion. "It's not the first time I've heard that question, 'Are you trying to break the mold?'" he says a little wearily. "But I'm not trying to destroy an image or manipulate anything; I'm trying to create something.I did a pretty cool movie and I'm proud of it. That's all there is to it."

Bailey and Barbato saw Culkin and Alig as flip sides of the same celebrity coin. "I had all the fame anyone could want, and I ran away from it," Culkin observes, "whereas Michael had this constant need for attention that could never really be satisfied. It was interesting for me to get inside his skin and find out what that was all about. Why was it that he felt compelled to be famous? And why did that desire for fame turn so deadly?"

Despite his self-enforced career hiatus, Culkin remains a popular figure. "People still recognize me all the time on the street," he says, laughing. "The first thing they say when they stop me is, 'Where have you been?' The second comment they make is always, 'Oh, you've grown up.' I'm not one of those actors who needs the media spotlight all the time to feel gratified. I'm happy to do one project a year and take the rest of the year off as long as that project is special."

The thought of Culkin playing Alig must have seemed like a stroke of genius to Bailey and Barbato, not to mention a potential publicity windfall. Culkin was a sexual fantasy figure to Alig, which provides a kinky twist to the casting. Bailey told me that he wouldn't have made the movie if Culkin had turned him down; he couldn't think of anybody else to play the part.

So was Culkin worried that he might end up glamorizing the person who had committed probably the grisliest crime in the annals of clubland? "Alig did a very bad thing," he replies. "He doesn't come off as a hero in the movie. But there are sympathetic moments; otherwise the audience wouldn't care. And the killing is less bloody in the movie than it was in real life; I didn't want it to be a gory movie, like a slasher flick. We wanted to make it real, but at the same time we didn't want to make it exploitative. It's a fine line."

When asked why he thinks Michael did what he did, Culkin provides a one-word reply: "Drugs." But, I point out, there are plenty of people who take plenty of drugs who don't end up dismembering their roommate. "That's true," Culkin admits. "I actually went to see Michael in prison, and I asked him, 'Why did you do it?' He told me that he didn't really remember it. He was very hazy about some of the details. And he lied about a lot of stuff. He told me he never did heroin and he never used needles. He also said that he couldn't remember whether he poured Drano down Angel's throat or injected him with it. We figured out he must have poured the Drano down his mouth, because, during the filming, we tried to put Drano in a needle and it didn't work. The liquid was too thick."

With the nightlife movement he led, Alig tried to create a fantasy childhood for adults, where grown-up responsibilities took a backseat to fun and play. Perhaps he was attempting to erase grim memories of his real childhood -- a father who abandoned him at an early age, a mother who sent him to be raised by surrogate parents and a family history of mental illness. Alig was also gay-bashed throughout his school years and suffered crippling bouts of self-loathing brought on by the shame he felt about his sexuality. "A lot of Michael's problems stem from his childhood and his relationship with his mother," Culkin agrees. "There's a large element of self-hatred in Michael. He liked getting cut up. He got himself thrown through a plate-glass window. There wasn't a time when he didn't have some mark or mutilation on his body."

To prepare for the role, Culkin watched a lot of old videos of Alig's outlaw parties. Initially, he was simply impressed by the crazy outfits. But he could see how Alig's bashes took on an increasingly desperate atmosphere over time. "The parties kept getting darker and darker and nastier and nastier," he says. "The more power he had, the uglier he became. He would pee on people, because he knew he would get away with it."

Culkin went to a voice coach to help him catch Alig's Midwestern accent. And he practiced campy dialogue over the phone with Seth Green, whose dead-on impersonation of Alig's longtime friend James St. James is one of the highlights of the movie. Culkin also tried to ape Alig's body language. "One thing I was worried about was the walk," he says, chuckling. "Michael has a very specific shuffle. And I'm like 'How am I going to remember to do that over time?' Then I tried on a pair of six-inch platforms he used to wear, and as soon as you put on the shoes, you just naturally shuffle your feet and swing your arms like Michael did."

I was surprised to find out that he didn't think it was necessary to go out nightclubbing as part of his research. "I'm not a nightclub person," he explains. "Anyway, the club-kid world doesn't really exist anymore, and there doesn't seem to be anything that's taken its place. I did go to one club-kid party, but it was sad, like a high-school re-union where everybody had gotten old and fat."

He did consider taking Special K, the animal tranquilizer that gave the Limelight's out-of-control festivities such a zombie-like edge, but finally decided not to. "You hear stories about actors doing it for the part," he says, "and the next thing you know, they're in rehab." I point out that K isn't considered physically addictive. "I know," he replies. "I've tried a bunch of things, but I've never done K or heroin."

Toward the end of the interview, Culkin objects to my description of Party Monster as "a twisted gay buddy movie." "There are gay characters, but it's not a gay movie," he protests. "We didn't want to be pigeonholed. We address the relationship with Keoki [Alig's erstwhile lover], but we didn't want the movie to be seen as something only gay people would be interested in."

Culkin's next release will be another low-budget movie, Saved, a comedy about a Christian community in the Midwest (co-starring Jena Malone and Mandy Moore). Has he given up on big-budget Hollywood films for good? Will he be content to do only small independent projects? "Most of the offers I get from Hollywood are for teen comedies," he says with a grimace. "My manager thinks I'm crazy for turning down all that money, but I'm very picky. I'd made enough money by the time I was 12 to never have to work again, so it's not about a big check with me. It's about finding unique, one-of-a-kind films that I would want to see myself. I think Party Monster is one of those."

Haircut and grooming by Moiz Alladina at Kramer & Kramer * Stylist's Assistant: Jessica Fisher