Heath Ledger's performance in 2008's The Dark Knight was arguably the best performance of the Joker ever put on screen. It was a performance that both inspired millions of people's Halloween costumes in the years since, and even inspired Timothée Chalamet to pursue acting. Plus, it is too #1 choice on /Heath Ledger's Movie List of Best Performancesa feat made all the more impressive by how stacked Ledger's filmography was already. Even people who hated the movie can agree that Ledger nailed it here, and in the 17 years since, Hollywood has tried in vain to capture what made Ledger's version so special.

One of the many elements that contributed to Ledger's understanding of the character was the book A Clockwork Orange by Anthony Burgess. Similar to Kubrick's 1972 film of the same namethis book is about an evil, chaotic young man who just seems to like watching the world burn. Alex, the main character of the book, is someone who doesn't have a clear story that explains why he is so evil; he simply has an appetite for depraved violence and has very little hesitation in indulging it. Sounds familiar, right? Christopher Nolan certainly thought so, which may be why he gave Ledger the book to read before production began.

"We cast (Ledger) before the script was even written, so he had a very long time to obsess over what he was going to do," Nolan explained in 2018 IndieWire Interview. "I sent him material - for example, I had him read 'A Clockwork Orange.' Nolan didn't explain much why, but he didn't need to. Not only does Alex DeLarge look a lot like the Joker, but he also connects with audiences for similar reasons. There's something fascinating about a shameless villain who works without any apparent rhyme or reason. Alex and the Joker are both terrifying and revolting, sure, but many readers and viewers find it amusing to see what craziness he does next.

Arguably the most relevant part about Clockwork Orange, at least as it relates to Ledger's Joker, is the final chapter that was cut from the original American publication and thus was subsequently not included in Kubrick's adaptation. The final chapter shows Alex finally having some sort of epiphany, realizing that he doesn't actually want to continue down this path of senseless violence. A surprising bit of hope that helps prove the book is not as nihilistic as its critics have assumed.

In his introduction to the 1986 edition, the first American edition of the book to include that salutary final chapter, Burgess explained how he believed his book had been somewhat misunderstood by the masses, and his final chapter aimed to make a more optimistic case for nature of humanity, that everyone (even Alex) has free will and the ability to improve. However, the much darker thematic conclusion laid out in the original American release - and the subsequent film adaptation based on it - is the one that has stuck with most people.

It's similar to how Ledger's Joker is often portrayed as a truly nihilistic agent of chaos, someone who really is just as evil, random and unplanned as he claims to be. It's an interpretation that misses out on several of the character's best layers—mainly the fact that this Joker spends a lot of time planning things and isn't actually motivated by the sheer desire to watch the world burn. This Joker is a bitter, insecure man who wants to prove to Batman that anyone can become as bad as him, and when the ferrymen choose not to blow each other up, he is definitely (at least as far as the movie is concerned) proven not to be in right. .

Despite its understandable reputation as a darker Batman film, The Dark Knight is more optimistic in its outlook on the world than it often gets credit for. I'm not sure Nolan had that part of the book's legacy in mind when he recommended it to Ledger, but it certainly makes for an intriguing connection.