More than 500 people had good reason to carouse into the creepy early-a.m. hours Friday morning: The midnight release of a vampire movie, of course.

Hundreds of viewers — 550 to be exact, according to Hollywood South Wind 12 house manager Jon Kelly — flocked to the south Lawrence theater for two showings of “New Moon,” the second film installment in the popular “Twilight” series.

Kelly said the first viewers started to come through theater doors at about 3:00 p.m. Thursday. By 10:00 p.m., the line of attendees had grown so long that it had bunched into a mass in the middle of the theater lobby, despite the staff’s attempts to straighten the rows.

But “New Moon” fans didn’t merely wander up to the counter expecting available tickets the day of the show. Attending these special showings took a bit of forethought.

“We got our tickets like three weeks ago,” said Natalie Langford, a Kansas University senior who came with a group of friends. “We heard they were selling out fast.”

Langford and her group attended the 12:05 a.m. showing: They were about a week too late to snare seats in the midnight showing.

“We got tickets a month ago online,” said DeAnna Thompson, a sixth grade teacher at Eudora Middle School whose group got tickets for the midnight screening. “So we’ve had them for a month and we heard it sold out pretty soon after that.”

Langford may have been among the last to purchase tickets for the pair of late-night Lawrence showings. Kelly said tickets were completely sold out three weeks in advance.

“New Moon,” which opens in earnest later Friday, is the sequel to the 2008 film “Twilight.” The movies are based on a series of novels focused on vampires, written by Stephanie Meyer. According to The Los Angeles Times, the first “Twilight” movie earned $69.6M on its first weekend one year ago. “New Moon” is expected to fare even better at the box office, and could top $100M on its first weekend.

Among the Thursday-night theater-goers were people both young and old, male and female. But viewers’ reasons for staying up late weren’t too different:

“I read all the books and I just loved them,” Langford said. “I was a little disappointed in the first Twilight (movie), but now they have a new director and I think it’s going to be really good. We wanted to be the first to see it, and its fun to see all the people out.”

Said Thompson: “I’m a schoolteacher, and I read the series myself and I fell in love with it.”