Heath Ledger’s endless dedication to each and every role of his is certainly no mystery, but his preparation for his role as the villainous Joker in The Dark Knight intrigues people even to this day.

Director Christopher Nolan and cast members have spoken at great lengths about Ledger’s fierce commitment to the role since the film’s release and Ledger’s heartbreaking passing in early 2008.

Fans of Ledger and of The Joker now have a chance to really see how Ledger created his version of the Joker in a new documentary.

A German documentary that chronicles Heath Ledger’s life gives viewers a glimpse at how Ledger’s Joker came to be through his Joker diary.

A scene from the upcoming documentary shows Kim Ledger, Heath Ledger’s father, going through a diary Ledger kept in preparation for his role as The Joker; the diary is loaded with images of the Batman comics, Alex DeLearge from A Clockwork Orange, hyenas, and playing cards, along with “Chaos” written multiple times in all caps while being highlighted green.

Kim Ledger comments, “He pretty well locked himself up in a hotel, in his apartment, for a month or so, to sort of galvanize the upcoming character in his own mind. That was typical of Heath on any movie. He would certainly immerse himself in the upcoming character. I think this was just a whole new level.”

Heath Ledger passed away on January 22^nd, 2008 and the void he left in both the film industry and in fan’s hearts will never truly go away. A young and bright star was lost that day and Ledger’s performance in The Dark Knight is one of his last; his very last role being his incomplete work in The Imaginarium of Doctor Parnassus.

Ledger received critical acclaim for his performance as The Joker and he has won a grand total of 32 awards, including a posthumous Oscar, for his game-changing portrayal. Ledger’s Oscar can be seen in the clip of the documentary.

Check out the documentary segment down below!