As a response to his own “Arkham Asylum: A Serious House on Serious Earth,” Morrison had continued his themes of the duality of Joker and the Batman in “The Clown at Midnight.” Having established with “Arkham” that the Joker had a sort of “super-sanity” and that he shifted between personalities,” Morrison explored the idea further in “The Clown at Midnight,” by showing that each time the Joker escaped, one of those new personalities would emerge.
Morrison says no one read these issues, Heath Ledger did and copied salient character points into his diary. Follow the link to read the entire article at Splash Page. And for an incredibly insightful article on Heath Ledger's performance, read LA Times Theatre Critic Charles McNulty's analysis on Heath Ledger In 'Dark Knight': Bravo!
Ledger isn't just after sick physical comedy with his slouch, jack-in-the-box spring and demonic head roll -- he's jotting down notes in a lengthy psychiatric case file. Quite amazing given the temptation to break loose of all mundane restraints, nothing's overdone -- not even the reptilian tongue, which emerges with the punctuating timeliness of an exclamation mark.
But it's through Ledger's eyes that we can peer into the actor's bottomless conviction and track the scurrying-rodent logic of his character's inexplicable evil. Maniacs who fly planes into buildings don't second-guess their distorted reality, and Ledger ambles around Joker's fun-house mind with an unshockable comfort. The film tosses off cryptic remarks about the Joker's brutal upbringing, but it's Ledger's antic disposition that lets us understand the traumatic past as a slippery myth that can never adequately explain malignant behavior.