Writer/director Joss Whedon's big-screen follow-up to his cult TV series "Firefly" finds the crew of the space freighter Serenity trying to keep the mysterious sister of the ship's doctor safe from the sinister Alliance. As the craft's heroic captain attempts to avoid an Alliance operative and figure out the secret of the enigmatic girl, the fate of the universe lies in the balance. Extraordinary sci-fi adventure stars Nathan Fillion, Gina Torres, Adam Baldwin, Sean Maher, and Summer Glau.