USA Today has published a look at upcoming video games which includes a mention of Batman: Arkham City and reveals how the game will open:
Batman’s adventure is bigger in the sequel to Arkham Asylum, one of 2009’s top games. Set 18 months after Batman’s defeat of the Joker in the previous game, the new title is five times bigger, says Dax Ginn of development studio Rocksteady. Arkham Asylum "was primarily an indoors kind of layout," he says. "We wanted to take the action to the streets of Gotham."
The game starts with Batman learning that Catwoman has been taken captive by Two-Face. "All these main criminal masterminds have their own agendas," Ginn says. "Two-Face is looking to establish himself as the guy to be feared and the gang to be joined." Look for the Joker and Harley Quinn, too.