Vanessa Hudgens in Zack Snyder's "Sucker Punch"

Vanessa Hudgens is growing up.  The "High School Musical" star is joining the cast of Zack Snyder's latest fantasy thriller.

Credit: AP Photo/Chris Pizzello

Details are slowly leaking about Zack Snyder's follow up to "Watchmen," an original script entitled "Sucker Punch."  According to The Hollywood Reporter, Snyder has lined up a cast of intriguing young actresses for the fantasy thriller including Amanda Seyfriend, Vanessa Hudgens, Emma Stone, Abbie Cornish and Evan Rachel Wood.

The 1950s period piece would find Seyfriend playing Babydoll, a girl  confined to a mental institution by her stepfather and under orders to be lobotomized within five days.  To escape the trauma, the young woman imagines an alternate reality where she begins planning her escape.  In that world, she needs to steal five objects to help get her out before she is "deflowered by a vile man."

Snyder co-wrote the screenplay with Steve Shibuya and described the fantasy world to the trade as "'Alice in Wonderland' with machine guns."  The imaginary universe would mix elements such as dragons, B-52 bombers and brothels (basically, "Girl, Interrupted" with CG).

With Seyfriend negotiating for the lead role, the rest of the cast is set to play Babydoll's fellow inmates who join her on the otherworldly journey.  Hudgens would play Blondie, Cornish would portray Sweet Pea, Wood is set for Rocket and Stone is on deck for Amber.

Seyfriend is in high demand these days.  The "Big Love" star appeared opposite Megan Fox in this September's "Jennifer's Body"  and is currently shooting Atom Egoyan's new drama "Chloe."

As for Hudgens, this project is a big step for the former "High School Musical" star.  Her next picture is another teen themed endeavor, "Bandslam," but this would clearly be the most adult project for the former Disney protege.  

Cornish hasn't appeared on screen since last year's long-delayed drama "Stop-Loss."  

"Superbad's" Emma Stone starred in last summer's surprise hit "The House Bunny" and will be seen this summer in "Ghosts of Girlfriends Past."  She recently finished production on the comedy "Paper Man" and is currently shooting "Zombieland."

Wood just played Mickey Rourke's estranged daughter in "The Wrestler" and has a role in Woody Allen's next romantic comedy, "Whatever Works."

An official start date for the Warner Bros. release has not been announced as of yet.