From PEOPLE Magazine Click to enlarge
Even for die-hard New York City clubbers, it's a late night. But although it's nearly dawn, Mary-Kate Olsen is still going strong. The 21-year-old actress has been on her feet for hours at Manhattan hot spot Beatrice Inn, celebrating Valentine's Day with her boyfriend, artist Nate Lowman, 29, drinking Stella Artois beers and vodka and sodas, chain-smoking Marlboro Reds and, every once in a while, ducking behind a booth with pals for privacy. She's ordered her three bodyguards to give her space, so they keep their distance, waiting for the night to end. Only it doesn't. After the bar closes at 4:30 a.m., Mary-Kate spends an hour in an upstairs lounge before heading to another club, telling pals, "We're going to keep partying."

Not so long ago, the names Mary-Kate and Ashley were synonymous with good clean fun. But these days the Olsens are arguably better known for burning the candle at both ends. Fixtures at exclusive nightspots like the Beatrice Inn and L.A.'s Chateau Marmont, Mary-Kate and her more low-key sister are at the center of a bicoastal, bar-hopping party scene in which insiders say drugs are common. It is the same fast-lane lifestyle that ensnared the young actor Heath Ledger, whose Jan. 22 death from an accidental overdose of prescription drugs is now focusing attention on the Olsens—and particularly on Mary-Kate, who casually dated Ledger for three months before his death (she was also the first person notified by Ledger's massage therapist, who found his body, and she sent three of her own bodyguards to his loft). And in the wake of Ledger's death, the Olsens don't seem to have slowed down: Just two days after the tragedy, both sisters were out together hitting clubs on Manhattan's Lower East Side. "They are young girls, they have money, and they like to party," says someone close to the Olsens, who turned 21 last July. "I wouldn't call them out of control, but I've seen them get pretty wild."

Even in the rarefied, celebrity-driven world they inhabit, the Olsens are seen as mysterious wraiths teetering on high heels, seldom removing their sunglasses or speaking to anyone outside a clique of old friends—many of them the children of Hollywood moguls. Most of the dozens of friends and associates interviewed for this story (the Olsens declined comment) say there are only two people allowed full access to their inner circle: themselves. "They are cold," says a pal. "They're not mean like Paris or Lindsay, but they are really only close to their boyfriends and each other. They're kind of emotionally uninterested in friends. We aren't talking about normal people here."

Then again, theirs have hardly been normal lives. At 9 months, the two Sherman Oaks, Calif., natives were sharing the role of Michelle Tanner on the family-friendly sitcom Full House, a part that helped make them Gen Y icons. A lucrative series of home videos and licensing deals followed, creating a billion dollar entertainment empire—and a combined net worth of some $300 million for the Olsens—all before they turned 18. "The work we did wasn't about acting," Mary-Kate told ENTERTAINMENT WEEKLY last September. "It was about pleasing people and making kids smile." By the time both young women enrolled at New York University in 2004, cracks in that facade were starting to show. After a family intervention, Mary-Kate Olsen spent six weeks at Utah's Cirque Lodge rehab center to treat an eating disorder. Both sisters soon left NYU—and became better known as bizarrely garbed fashionistas with a penchant for dancing on nightclub tables and subsisting on cigarettes, sweets and Starbucks lattes. "They both changed a lot; they got real crazy," says someone familiar with the twins. "They definitely started going a little bit hardcore."

Isolated from peers by their vast wealth and fame, Mary-Kate, the edgier sister (she is known to write dark poetry and has seen the S&M romantic comedy Secretary "a hundred times," says a friend) and Ashley, more laid-back and stylish (she interned for designer Zac Posen), have had separate apartments in Manhattan as well as homes in Los Angeles. Older by two minutes, "Ashley tries to be mature," says a source. "Mary-Kate is more amped to party." At one recent event, Mary-Kate "was dancing with her arms up in the air, doing this spastic move with her arms," says a source. "She was the only one dancing and everyone was looking at her." At around 5'2", the pint-size sisters are dwarfed by massive bodyguards when they duck into Manhattan boutique Jeffrey, where they have a personal shopper, and Barneys, where they hit the basement spa for regular $90 eyebrow pluckings.

Yet they also spend a lot of time in their Manhattan office, working mainly on their three clothing lines (their Mary-Kate and Ashley line sells at Wal-Mart, while their two newer lines, the Row and Elizabeth and James, are more upscale and, say sources in the industry, likely to be successful). Ashley is more focused on their fashion businesses, while Mary-Kate "is really trying to make the acting thing work," says a friend. She played a Bible-thumping pot dealer on the TV show Weeds and a young hippie in the indie hit The Wackness, both to critical acclaim. "She came in with no entourage, very professional," says Weeds creator Jenji Kohan. "She was a very natural actress; she earned the role."

Perhaps the most startling change in their lives is that the Olsens have, says one source, "drifted from each other. They have major issues as sisters. Ashley thinks Mary-Kate follows her too much. Ashley is like, 'Get your own life. Get your own friends.'" Lately Ashley has been hanging out with her new pal, designer Estee Stanley, 38; the two partied in Aspen over the New Year. Yet despite their differences, the Olsens do still lean on each other. After Ledger's death—"a devastating blow to Mary-Kate," says a friend—Ashley flew to New York City to be with her sister. "If they didn't have each other, they wouldn't be where they are now," says a source. "They are best friends."

What's more, neither sister seems interested in changing her ways to satisfy critics. Designer Jenni Kayne, who knows both Olsens, shrugs off reports about their wild behavior. "I don't see that," says Kayne. "I see their clothes hanging up at Bergdorf's and Barneys. I see success. And everyone else should see that too."

What the Olsens see is a world only they can fully understand. In 2004 Ashley told PEOPLE about an essay she wrote for her NYU application, which compared her chaotic life to the abstract painting "Number One" by Jackson Pollock. "Some people look at it as complete mayhem, or just paint splattered on a canvas, and yet there's so much emotion behind it," Ashley explained. "Some people will never, ever get that. No one knows what it's been like for us, and we don't expect anyone to know, good, bad or amazing. But we do expect people to respect the decisions we make."

  • Contributors:
  • Alyssa Shelasky/New York City,
  • Lesley Messer/New York City,
  • Hitha Prabhakar/New York City,
  • Ryan Pienciak/New York City,
  • Aaron Parsley/New York City,
  • Lisa Ingrassia/Los Angeles,
  • Jen Garcia/Los Angeles,
  • Mary Margaret/Los Angeles,
  • Amy Keith/Los Angeles.