Costumed fans line up outside of the soon-to-be-closed AMC Loews Harvard Square 5 to see one of the last midnight screenings of "The Rocky Horror Picture Show."

Seasoned transvestites and “Rocky Horror” virgins alike turned up Saturday night for the Full Body Cast's third-to-last midnight showing of “The Rocky Horror Picture Show” at the soon-to-be-closed AMC Loews Harvard Square 5 theater.

Most attendees said that they bought their tickets after hearing earlier in the week that the theater was closing. When a cast member announced that the last performance at the AMC theater in Harvard Square would be on July 7, she was greeted with boos from the audience.

“I’ve been going since it was back at the [Exeter Street Theater],” said Cambridge resident Stephen Moore. “I was really sad to hear it was closing. It’s an institution.”

But the show’s sold-out audience was not limited to regulars.

“I just turned 17,” said “Rocky Horror” virgin Renee Nickerson, who was at the show with several of her friends. “It’s a birthday party type of thing.”

The show is open only to those 17 and older. Both first-time attendees and veterans shared similar expectations for the show, which includes actors performing in front of the screening of the cult film and audience members gyrating in the aisles.

“Mayhem,” predicted Cambridge resident Devlyn Kelly, who had also just turned 17.

“Total craziness,” said Gail Bennett, a friend of Moore who has been going to shows since the movie premiered in 1975.

For Cambridge resident Hayden Schultz, the show was an opportunity to educate a younger generation.

“I saw this in college when it came out,” Schultz said. “My son had neither seen it nor heard of it, so I thought it’d be fun to bring him. Ever since I bought the tickets, ‘Time Warp’ has been stuck in my brain.”

In addition to its final two midnight showings, the Full Body Cast will present a 9 p.m. show on July 7.

—Staff writer Petey E. Menz can be reached at menz@college.harvard.edu.