Heath Ledger - in his own words
What would Heath Ledger have said about The Dark Knight and his part in it had he not tragically died earlier this year? writes Victor Olliver.
No idea. But we can piece together what he said about his celebrated Joker in the periods before and after the movie shoot - from interviews on YouTube, in the print media and on websites.
In most of these he knew the film would be an awesome success.
In a Dark Knight MTV News interview with Heath Ledger, posted on YouTube - it has drawn 7,555 comments and over 2.8m visits - he talks about The Joker.
"Playing the part was the most fun I ever had," he says. "It required a high level of energy.
"I was asked would I like to play the part and within five seconds I knew how to play it. My thoughts were identical to (director) Christopher Nolan's."
Ledger told journalist Daniel Robert Epstein before the Dark Knight shoot: "I definitely have something up my sleeve. I want to be very sinister.
"Tim Burton did a more fantastical kind of thing and Chris Nolan is doing nitty gritty handheld realism.
"I love what Jack Nicholson did (in Batman) and that is part of why I want to do that role. It would be murder if I tried to imitate what he did."
Ledger admitted he had a "no tights, no fights rule" which precluded him from playing comic book superheroes.
"I would just feel stupid," he told IGN. "I couldn't pull it off and there are other people who can perfectly, but I just couldn't take myself seriously.
"And I feel like The Joker is an opportunity for me to not take myself too seriously."
Once he had completed the shoot Ledger told MTV News: "It was an exhausting process. At the end of the day I couldn't move. I couldn't talk. I was absolutely wrecked."
He added: "Joker has zero empathy. A Clockwork Orange was a very early starting point for ideas."
He admitted Sid Vicious might have influenced his Joker a bit - another star who died way too young.