The stars were hiking up the red-carpeted steps of the Met. There was Julianne Moore, Jennifer Lopez, Salma Hayek, everyone. And hardly anyone was stopping to talk to The Transom. But wait—here was Christina Ricci, who said that getting ready for the evening had taken roughly two and a half hours, plus a lot of Red Bull. “I loved my dress” (a white velvet Calvin Klein), she said, “and I was so excited to wear it and show it to people, but at the same time it’s very nerve-wracking, because you’re like, ‘Ahhhhh! What if I say the wrong thing?’”

At least Ms. Ricci pronounced Poiret, the evening’s celebrated designer, correctly—unlike some plebes we could mention. “That’s somebody who really changed the world,” she said. “He really altered the way women dress, because he took away the corset—he gave us the bra! I mean, that’s one of the biggest inventions of the 20th century!” (The ample-bosomed starlet then confessed: “As soon as I found out about this, I went online and did a little research.”)

French designer Gilles Mendel, best known for his furs, made the inevitable comparison to the Oscars—where, he said, “I feel very much that I’m sort of like a foreigner. I’m like a guest. And when I come to this party tonight, it’s really like I am a member and the celebrities are our guests. It’s like a camaraderie. I feel very comfortable, even though it’s the most prestigious one.”

Indeed, many of the celebrities on the red carpet didn’t appear completely at ease.

“I have no idea,” said Parker Posey, asked to explain the importance of the Costume Gala. “I’ve never been here before.”

Whether it was that the actors felt it impertinent to suck up too much attention at a fashion-world event (unlikely), or that they just couldn’t wait to get inside and enjoy the so-called “Party of the Year,” most rushed past the hundreds of waiting reporters with nary a nod.

Kirsten Dunst, fresh off Spider-Man 3’s boffo box-office weekend, ran up the steps so fast that the train of her purple Yves Saint Laurent gown was positively bouncing.

“Kirsten! Kirsten!” they all screamed in vain. “I’ve never done anything so humiliating as this,” said one.

At around 8:15, The Transom decided to attempt a stroll through the museum doors, which were heavily guarded by Vogue editor Anna Wintour’s watchdogs. About 10 paces in, there came a tap on the shoulder, then a stern hand pressing against the back. It stayed there on the long, long walk down those blood-red steps to the street.

Spies inside later reported being greeted by a cage containing three peacocks. Breathe easy, PETA people: The cage was enormous.

Then, “everyone has to walk this gauntlet of servants lined up on either side,” said one attendee. At the end of the line was the queen, Ms. Wintour, flanked by the arguable belle of the ball, Cate Blanchett, in fringed gold Balenciaga.

Dinner was announced with a long Henry VIII—style trumpet fanfare. As the hungry hordes poured into the banquet room, they were greeted by Vogue editor at large André Leon Talley, draped in a giant navy tent-like cape, lounging on one of the many couches that lined the walls. “Welcome to my home,” he bellowed upon spotting his friend Donatella Versace, and then erupted into laughter.

Caviar on smoked salmon, veal and chocolate mousse were served. Then Jennifer Hudson performed. “She went on for a good 15 minutes,” said a witness. “Half the crowd was really into it, and half the crowd was just having none of it.”

Guests gushed further that the room’s décor was very “intimate” and “comfy,” despite the grandeur of the event. “It was very warm,” said hotelier André Balazs, who turned up later at an after-party at the Box on Chrystie Street. (The Olsen twins, Damon Dash style="letter-spacing: -0.1pt"> and Mick Jagger stopped by Mr. Chow’s first.) “I’ve never seen that room like that. You were surrounded by all these panels that were hand-painted murals on canvas …. And the whole room was sensual, and there was this sisal carpet. It was a very—strangely enough—intimate evening.”

Actress Rose McGowan didn’t agree. “There were a ton of people I don’t know,” said she, ravishing in J. Mendel, at the Box. “I get nervous around people I don’t know.” She said that she had been introduced to several doctors. Doctors! “You just look at all these people and you say, ‘I don’t know any of you, and I feel completely out of place.’ And you think, ‘Why am I here? You’re all very tall.’” She laughed a great toothy laugh.

“I’m not usually very serious about being myself, and then all of a sudden I felt as if I had to be serious,” Ms. McGowan continued. “So I acted.”

It was now 2 a.m., and the stuffing was clearly coming out of the evening. Many of the women had traded in their long gowns for cocktail dresses. Tuxedo ties swung free about the collar.

Lindsay Lohan swept in and was immediately ushered into the downstairs of the burlesque theater by its bearded proprietor, Simon Hammerstein.

And at the top of the stairs, Jennifer Connelly and her husband, Paul Bettany, were having a little tiff.

“You totally just walked away from me,” whined Mr. Bettany.

“No, I didn’t, honey,” pleaded Ms. Connelly.

“Yes, you did!”

The argument resolved itself quickly, and the couple headed arm-in-arm toward the main room. There, in a booth near the stage, were Mr. Jagger and the chain-smoking Ms. Dunst, sharing a booth.

Ms. McGowan and her new beau, Grindhouse director Robert Rodriguez, were on their way out. Mr. Rodriguez had opted not to attend the gala. “I heard what it was all about, and I was like, ‘I’ll turn right,’” he said. “I just wanted to come for the fun part.”