So, who exactly is going to be involved in the new movie "Serenity," based on Joss Whedon's failed "Firefly" series?

Well, one site -- Browncoats -- apparently got their hands on what they believe to be is a casting sheet for the upcoming film, which reveals some of the supporting characters. A casting sheet is sent to talent agencies to help them bring in the proper people for auditions for such roles.

According to the casting sheet, there are a dozen supporting roles that need to be cast, from somewhat larger roles, to more single-line roles.

One character is described as "The Operative," who is a government agent with wire-rimmed glasses ad neatly trimmed hair. However, don't let that nerdy exterior fool you. He's also an expert martial artist, assasin, investigator and tracker.

"Mr. Universe" is described as "an unkempt young man, sleep-deprived, over-caffeinated and kinda sweet." Apparently he's no Ahnold. The character also will have a lovebot, but will be the true nerd providing information through a variety of video feeds and monitors.

Other characters include the mostly unethical and unlikeable Dr. Mathis, British identical twins Mingo and Fanty, Inara's (Morena Baccarin) friend Sheydra from the Companion Training House, a female teacher for some flashback scenes, a hologram of Dr. Caron, Mr. Universe's lovebot Lenore, River Tam at 10, a young hostage in a heist, an ensign and a guard.

According to the casting sheet, filming will begin in June in Los Angeles. The cast includes the regular cast of characters including Nathan Fillion as Mal, Baccarin as Inara, Adam Baldwin as Jayne, Summer Glau as River Tam, Sean Maher as Simon, Jewel Staite as Kaylee, Gina Torres as Zoe and Alan Tudyk as Wash.

Please note that this casting sheet has not been confirmed by Mutant Enemy, and should be treated like any other rumor.

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