The "High School Musical" crew is growing up quickly.  Ashley Tisdale is trying to forge a music career beyond the tween set, Zac Efron is already ditching musicals for dramatic indie roles and now his longtime girlfriend, Vanessa Hudgens, is making the biggest leap of all.  The 20-year-old actress is about to begin production on Zack Snyder's highly anticipated new film "Sucker Punch." HitFix caught up with Hudgens earlier this week and she provided these exclusive details on her involvement in the project so far.

While Hudgens has shot two non-"HSM" movies over the past year, next month's "Bandslam" and "Beastly," she admits she's a little nervous about starring in Snyder's fantasy thriller.

"I'm not confident, but I know if I really, really set my mind to it then I can do it," Hudgens says. "I do not know what to expect. I've never been so excited and scared in my whole life."

Based on an original idea by Snyder and Steve Shibuya, "Sucker Punch" centers on a young girl ("Lemony Snicket's" Emily Browning) put into a mental institution by her evil stepfather.  In order to deal with the situation, she journeys to an alternative reality where she meets some characters she hopes will help her escape from her real life nightmare. Besides Hudgens and Browning, the film has reportedly also recruited Emma Stone, Evan Rachel Wood and Abbie CornishHudgens is itching to play the role of Blondie in the new flick who she describes as "really tough, really hard."

"It's very much an ensemble piece," Hudgens says.  "It's these five girls in this crazy fantasy land, but I don't know honestly.  I read the script and I have talked to Zack a little bit, but haven't really had any rehearsals or anything for it."

While production isn't expected to begin until September, Hudgens will head to Vancouver, BC in the next week or so to begin fight training, stunt choreography and dramatic rehearsals.  And if it's a Zack Snyder movie, she must be carrying some sort of weapon on screen, right?

"Yeah, oh yeah.  Yeah, I have weapons," Hudgens says smiling.  "I have a massive, massive gun.  Let's just say that."

Hudgens has also already worked with costume designer Michael Wilkinson ("Tron Legacy," "Watchmen") on Blondie's look, but wouldn't elaborate with any details.

After having spent the last few months shooting one picture and promoting "Bandslam" at the same time, Hudgens is going straight into production on the new flick without a break, but the last thing she's doing is complaining about it.

She says, "I'm in work mode, I could go for as long as I needed to.  And I'm genuinely excited about 'Sucker Punch.' I'm looking forward to it. I'll rest when I'm dead."