NEW YORK - NOVEMBER 13: Actor Heath Ledger attends the New York premiere of "I'm Not There" presented by The Cinema Society and Hogan at the Chelsea West Cinemas on November 13, 2007 in New York City. (Photo by Stephen Lovekin/Getty Images)
Heath Ledger attends the New York premiere of "I'm Not There" at the Chelsea West Cinemas in New York City on November 13, 2007. Stephen Lovekin—Getty Images

Heath Ledger's 'Joker' Diary Revealed in New Documentary

A German documentary about the life of Heath Ledger is giving a glimpse into how he created his chilling Joker for The Dark Knight.

A scene from the doc shows Ledger’s father, Kim Ledger, leafing through a diary his son kept while preparing for the role.

“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,” Kim Ledger said. “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.”

The diary is filled with images of playing cards, scenes from Batman comics, photos of hyenas, and stills of Alex DeLearge from A Clockwork Orange. The word “Chaos” can also be seen, written in caps and highlighted in green.

Ledger died in January 2008 at the age of 28. The following year, he was awarded a posthumous Oscar for his role as the Joker, and that statuette can be seen in the clip below as his father looks through the diary.

This article originally appeared on EW.com

Meet All the Actors Who Have Played Batman and Robin

Lewis Wilson And Douglas Croft In 'Batman'
Lewis Wilson was the first actor to play Batman on screen, with Douglas Croft joining him as the first Robin in the 1943 film Batman.Columbia Pictures—Getty Images
Lewis Wilson And Douglas Croft In 'Batman'
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