'The Dark Knight' also holds the distinction of being the top-grossing comic-book adaptation in history. In terms of overall performance, the film already ranks No. 8 among all-time box-office hits. The Dark Knight is a follow-up to 2005''s Batman Returns. Both films were directed by Christopher Nolan and star actor Christian Bale as the 'Caped Crusader'.
Interest in the sequel has been stoked by Heath Ledger''s edgy turn as the villainous Joker, in what turned out to be the Australian actor''s last completed role before he died of an accidental overdose of prescription pills in January.