Harvey Dent is the Backbone of Dark Knight
 

The Los Angeles Times talked to The Dark Knight director Christopher Nolan, who says that "Harvey Dent (Aaron Eckhart) is a tragic figure, and his story is the backbone of this film."

The Batman Begins helmer also mentioned that The Joker, played by Heather Ledger, "sort of cuts through the film -- he's got no story arc, he's just a force of nature tearing through. Heath has given an amazing performance in the role, it's really extraordinary."

He added that you shouldn't expect a lot of laughs. "It's a dark and complex story and the villains are dark and complex as well."

The Dark Knight opens in theaters on July 18.