At 11 a.m. on May 31, the final day of the Museum of Modern Art's magisterial retrospective of performance artist Marina Abramovic, an extraordinary thing happened at the museum.

A young woman in a flimsy floral sundress waited on deck as the next person to sit with Abramovic. A museum security guard gave her the requisite briefing on the process — there was, for instance, an enforced ten-minute limit on sitting sessions for the show's final day, to give more people a chance to have the experience — but she seemed only to half listen. Her hands fidgeted; she was visibly nervous. She appeared to have something up her sleeve.

In fact what she had up her sleeve was the removal of it. Which is to say, she approached the chair on which she would sit facing the artist and, once there, pulled her sundress over her head in one swift fluid motion to reveal her naked body. (Her friends later said they weren't sure whether the act was premeditated, but the lack of panties gave away some measure of advance planning.)

The guards' response was swift. They gathered around the woman, one of them draping around her a thick black blanket perhaps kept on the sidelines of Abramovic's arena for just such incidents. She burst into tears, protesting that she should still be allowed to sit with the artist. She was escorted from the atrium.

Here is a catalogue of the reactions to this incident. The guards and other museum professionals: looks that mixed alarm, consternation, and annoyance. The crowd of visitors waiting to sit with Abramovic: boos and hisses, presumably in response to the perceived injustice in quashing an act that seemed, on the face of it, somewhat in line with the brave spirit of Abramovic's own performances (note the multiple nude performers in the main part of the exhibition, six floors up.) The young woman's friends: prodigious tears of solidarity. Abramovic: stone-faced silence.

This young woman happened to be, according to Sarah Small, a friend who'd accompanied her to the exhibition, the young independent filmmaker Josephine Decker. (Attempts to interview Decker after the incident were thwarted when she was cornered by an HBO film crew that had been dashing around the museum dangling its boom mike into conversations; Decker was giving the film crew the raised-index-finger gesture that indicates, "can you give me a second," as she tried to regain her composure.)

Decker, as it turns out, along with others who who were sitting with Abramovic that day, had something in common with the artist: endurance. From Acconci to Beuys to Abramovic to Barney, endurance has been a common theme running through performance art. A lietmotif, even. It may in fact be the one quality that truly qualifies one to be a performance artist. It's what performance artists and marathon runners have in common, profound mental and physical endurance. And Decker and the others had endured something profound. Namely, a line.

By 8 a.m., with the bells of nearby St. Thomas Church ringing, the line of folks who had waited all night to sit with Abramovic stretched down the block, towards Sixth Avenue, past the Folk Art Museum. It was peppered with air mattresses, blankets, and pillows. Its first tranche consisted in folks who'd been back two or three times, and hadn't yet gotten to sit. Some were even back for a second night on the street.

"I got here 6 a.m. yesterday, and when it became clear at 5 p.m. that I wouldn't make it in I left the line inside and started the line outside and fell asleep," says Drew Denny, an energetic, blond 26-year-old grad student who had made the trip from Los Angeles just to sit with Abramovic. "I fell asleep, and someone must have called an ambulance because I woke up to this huge paramedic saying, 'You OK?' He gave us these blankets, and a hotel gave us a couple towels." Denny had canceled her flight back to L.A. the night before when she hadn't gotten to sit yet.

Had she camped out for an event before? "Yes, but only in protest of something or to cover something," she said. "I'm from Texas. In 2000 I sat outside the capital all night, to write about the election for my school newspaper." Anyone else? "Spin Doctors concert in 6th grade!" exclaimed 31-year-old Sarah Small. She then admitted that she'd sat in another New York line recently — the one at White Columns last summer, to audition for Bravo's new art reality show, which debuts on June 9. "I didn't sleep outside, but I came early in the morning," she said. "And ended up getting all the way to the very last round."

"It's the first time I've ever slept on the streets," said longtime New Yorker Ann-Sargent Wooster, an art history professor at New York School of Visual Arts. "But you should have heard the birds singing at 6 a.m. They were very excited." She suspected that she was probably the oldest person in line. "I'm the same age as Marina," she said.

One thing everyone waiting for a moment with Abramovic could agree on was that they didn't like the idea of VIPs — aside from the artist's fellow performers — getting special treatment at the show. They didn't like the idea of celebrities skipping the line, or even of a wheelchair-bound woman being able to jump ahead.

Because they went through something on that line. Certainly Josephine Decker and Sarah Small did. At one point in the wee hours of the morning, Small awoke to find that a homeless man with a pustulating facial wound had curled up next to her friend, thereby placing himself first in line. She was alarmed, but politely asked that if the man intended to wait in line to sit with Abramovic, he take his proper place at the end.

Indeed, a fair amount of solidarity developed in the line. Denny and Small described others recreating Abramovic's artwork late at night, effectively having staring contests amongst themselves. "We've been critiquing this artwork since 6 a.m. yesterday!" said Denny. A petition was being passed around asking people to pledge that if they got to sit with the artist, they would limit themselves to seven minutes in order to increase the chance that more of their fellow line-waiters would make it to the coveted seat.

And yet some in line felt ambivalent about the time limits. "Time limits are what will allow me to sit ultimately," said Denny. "The directive must have come from Marina. But it makes me feel a little awkward. It feels like a weird change in the artwork, like it might be a little compromised."

And like that, the ordeal of enduring the hard pavement and elements with no certainty of success was embraced, allowing a communion of sorts with Abramovic. Christina Thomopoulos, a 20-year-old NYU art student, had already sat with Abramovic and yet spent the night in line. "Waiting in line is an important part of this piece," she said. "And meeting all these people."