Shhh. Listen.

Was that a pin dropping? Perhaps the rustle of a turning page?

If the city seems unusually quiet this morning, you can bet it's because, at this very moment, thousands of Harry Potter fans are either nose deep in "Harry Potter and the Half-Blood Prince," or sleeping in after one of the many parties celebrating the book's midnight release.

The sixth installment of author J.K. Rowling's $1 billion series hit the shelves at midnight last night and, once again, bleary-eyed fans of all ages were there to snatch their pre-ordered copies.

With an initial U.S. print run of 10.8 million copies — believed to be the largest in history — the new book is poised to be the best-selling Harry Potter book yet.

The previous book, "Harry Potter and the Order of the Phoenix," sold 5 million copies in the first 24 hours after its release and 11 million in 12 weeks — the fastest-selling book ever.

"It'll be big," said Brian Mel-zack, owner of the local independent book chain Bestsellers. "But 10.8-million-big, that's the question. I guess we'll find out on Monday."

Melzack had his hands full yesterday as Harry Potter fans converged on his Koko Marina store for a pre-sale celebration that included coloring activities, fake tattoos and refreshments. Melzack said his store had taken in about 1,000 advance orders as of yesterday afternoon.

Still, Melzack said, the high-volume sales wouldn't necessarily add up to big profits for his business. To stay competitive with the national chain stores, Melzack had to match the standard 30 percent opening-weekend discount on the book and throw in a $5 gift certificate for advance orders.

Like other booksellers, Melzack spent the week rebuffing the inevitable tide of people trying to get copies of the book before today's official release.

"If you want a book, sure, you can have one," Melzack said yesterday. "But if you had one, of course, I'd have to kill you."

As usual, Borders and Borders Express pulled out all the stops with their Midnight Magic Parties.

The Borders at Ward Centre featured a half-dozen activity stations, prize giveaways, express cafe service (with a full menu of Harry Potter themed delectables) and a host of costumed guests.

Actress Alissa Joy Lee, 27, was sent over by a temp agency to walk the aisles as Prof. McGonagall — apparently after invoking a powerful wrinkle-removing spell.

"She's very stern," said Lee, trying to stay in character. "I'm trying not to smile too much."

Street magician Travis Rosales was hired to entertain the waiting crowd with his signature spoon-bending tricks. With a temporary lightning bolt Sharpie-d onto his forehead, he was a surprisingly good approximation of Harry Potter — mop top and nose ring excepted.

"Everybody wants to believe in something they can't explain," said Rosales about the book's supernatural drawing power.

To keep the lines manageable, the store issued line-place tickets and used a "sorting hat" quiz to divide buyers into Hogwarts-themed academic houses.

Cathy Seifert, 52, of Ko Olina, rushed to the store at 10:30 a.m., hoping to snag an early ticket (the Borders store in Waikele began issuing tickets at 9 a.m.). She was disappointed but undeterred when told that the Ward store was sticking with it's planned 5 p.m. handout time.

Seifert, who reads Harry Potter-related fan fiction online and owns both the U.S. and British editions of each of the previous five books, said she had to be careful not to listen to rumors about the book. Two years ago, a malicious Harry-hater sent her Yahoo group an e-mail that revealed the book's secret in the subject line.

Gypsy Madden, a 27-year-old HMSA employee from Hawai'i Kai, arrived at Borders yesterday in a homemade costume so dead-on that people in the snaking ticket line might have thought the boy wizard was playing hooky from Hogwarts.

"These release parties are so much fun," said Madden. "I think it will be even bigger this time than two years ago."

Julia Koga, 29, of Ala Moana, came dressed in a Gryffindor robe but was identified as brainy Ravenclaw stock by the sorting hat quiz. She couldn't have been happier.

"Ravenclaw is my favorite," she said. "I feel like it's the (house) that fits my personality best."

It's a safe bet that Koga, a psychology student at the University of Hawai'i, is applying some of that Ravenclaw studiousness to her novel-reading today.

"Last time I started reading as soon as I got home," she said. "I read until I got tired, then I finished the book the next day."