Warner announces 'Dark Knight' plans LOS ANGELES (UPI) -- Warner Bros. in Los Angeles has announced that it will start production early next year on the sixth Batman film, "The Dark Knight." Christian Bale is back as the caped crusader in the next installment of the bat saga, with Heath Ledger joining the cast as the villainous Joker, Daily Variety reported Tuesday. Christopher Nolan will be returning to the director's chair, with his brother, Jonah Nolan, penning the script. "Batman Begins," the most recent Batman film, took in $205 million domestically and $166 million overseas. It's likely "The Dark Knight" will be slotted into the summer 2008 lineup, with production starting next winter.