A journal Heath Ledger kept in the final days of his life is featured in a new documentary series about the young Hollywood star's death.

In 2007, Heath Ledger landed one of the biggest cinematic roles of his career--playing the lead villain in Christopher Nolan's "The Dark Knight." In the film, the award-winning director sought to create a villain that would defy every conventional image of movie "evil," challenging his star to break bold new ground.

Ledger as The Joker, photo courtesy of Warner Bros.

To prepare for the demanding role, the young actor closed himself off from the world, living completely isolated and alone in a hotel room for a month in order to develop the character:

 “I sat around in a hotel room in London for about a month, locked myself away, formed a little diary and experimented with voices,” Ledger said of the filming process. “I ended up landing more in the realm of a psychopath,  someone with very little to no conscience towards his acts. He’s just an absolute sociopath, a cold-blooded, mass-murdering clown, and Chris has given me free rein.”

As Ledger was working on physical and emotional characteristics, he kept a diary. The journal contains thoughts and emotions Ledger poured onto the pages of the diary, not as himself but as his homicidal Joker character, recording each and every sick and twisted thought the psychopathic killer may have had.

It’s that grueling process that many have speculated ultimately took a severe toll on the young star. He frequently complained of sleep troubles, and resorted to pills to help him. Ledger died on Jan. 22, 2008 from an accidental overdose of prescription drugs. "The Dark Knight" had not yet been released.

In a new documentary series, “Too Young To Die,” the actor’s father Kim Ledger shares the journal with audiences for the first time.

The clip is in French (with a French narrator translating over Ledger's father as he shares the diary).  Here is the translation:

"This is the Joker's diary.

In order to inhabit his character, he (Heath) locked himself up in a hotel room for weeks.

He would do that. He liked to dive into his characters, but this time he really took it up a notch."

"The hospital scene is interesting because when he was a kid, his sister Kate liked to dress him up as a nurse. He was really funny like that. He also was in the movie.

This is a make-up test which was done eight months before. Before the end of the shooting he wrote "bye bye" on the back of the page. It was hard to see this.'

 

Ledger was posthumously awarded the Oscar for Best Supporting Actor, the first time a deceased actor or actress has received the award.