As Dr. Horrible, the protagonist and would-be villain of the movie “Dr. Horrible’s Sing-Along Blog,” made his final pitch to join the Evil League of Evil Saturday night, it was like he was right there in front of the audience, doing his worst to intimidate them. That’s because he was.

Taking a cue from “The Rocky Horror Picture Show,” some local actors brought the Internet sensation to life with a shadow cast performance at Grand Ledge’s Sun Theatre, as the movie was projected behind them.

“Dr. Horrible’s Sing-Along Blog” is a short, three-part movie that surfaced online during the Writers Guild of America’s strike of 2008. The musical tragicomedy stars Neil Patrick Harris, as Dr. Horrible, an aspiring super villain who just wants to bring social change to the world. The story follows Dr. Horrible as he attempts to gain entrance to the Evil League of Evil, chases after romantic interest Penny and battles with his arch nemesis, the cheesy and insincere Captain Hammer.

The shadow cast who acted along with the movie Saturday night consisted of a group of friends obsessed with the movie led by Rachel Diamond, who played Captain Hammer. Diamond came up with the idea to do a screening at the Sun, and she got some friends together to perform along with it.

The college-age cast, all former students of Grand Ledge High School, practiced once a week for about three months to prepare for the performance.

The actors dressed to match characters in the movie and pantomimed the action as it happened onscreen, mouthing the words and emulating the movements of their respective characters. The actors also added some new elements to the show, as they interacted with the audience before and during the movie, initiating them into the Evil League of Evil and bringing the action into the aisles. Penny tried to get audience members to sign a petition.

K.C. Doty, who played Dr. Horrible’s secret identity, Billy, said it was difficult to emulate exactly what was happening onscreen, because it left no room for creative liberty. Diamond agreed that matching the onscreen action was a challenge, but she also felt it relieved some pressure, because the audience’s attention was split.

Primarily a comedy, the movie won many laughs Saturday night, but it also delves deeper into the irony of Dr. Horrible’s rise to evil. Dr. Horrible/Billy just wants to change the world for the better, but he sees no way to inspire change except takeover. Captain Hammer, the supposed “superhero” of the town, saves the day to win fame and get ladies.

“You see how a superhero becomes a superhero, but you never see how a villain becomes a villain,” said K.C. Doty, who played Billy. “You see the evil of heartache. I think it’s hilarious, but it’s interesting that it’s really deep, too.”

Before the show, Courtney Bonner (Penny) said she loved the movie and couldn’t get its music out of her head. “I was signing the songs in the shower this morning,” she said before the show.

The fans were as enthusiastic as the performers, and some even dressed as characters from the film. Josh Florian and a handful of friends came in elaborate costumes of many of the characters. Florian dressed up as Dr. Horrible himself, complete with white lab coat and goggles. “I watched it once and got hooked,” he said. “It’s too catchy. I’ll be at work and it’ll just pop into my head.”