Want to find out how he got those scars? Well, you're going to. The Todd Phillips-directed, Martin Scorsese-produced Joker origin film is, in fact, a prequel to The Dark Knight , exploring how Heath Ledger's incomparable version of the Clown Prince of Crime came to be.

Out of all the projects currently in the pipeline at DC Films, perhaps the most intriguing is the Joker standalone movie. Not part of the DCEU but the first in what could be an expanding “Elseworlds-style” banner, it will chart the origins of the Joker in 1980s Gotham, evoking the crime films of producer Martin Scorsese. It's been repeatedly rumored that Joaquin Phoenix is the frontrunner for the role , but all that's known plotwise is that it will tell a story akin to Scorsese's The King of Comedy and Alan Moore's icon Joker alt-origin, The Killing Joke. However, that won't be the only thing familiar.

On Friday, Warner Bros. released an updated production slate of movies intended for internal use that included an “UNTITLED JOKER ORIGIN MOVIE” – the first official word by the studio the project is in development – that confirms Phillips and Scorsese's involvement. However, what's really interesting is the plot synopsis, which reveals it's actually a prequel to Christopher Nolan's The Dark Knight:

20 years before Batman saved the city in THE DARK KNIGHT TRILOGY, Gotham was a dangerous place. In the crime-ridden Narrows, one man tries to escape his unfortunate lot through a passion for theatrics and stand-up comedy. However, one bad day is all it takes in this city, and soon the well-meaning man has become the most dangerous criminal of all: the Joker. Directed by Academy Award Nominee Todd Phillips (WAR DOGS) and produced by Academy Award Winner Martin Scorsese (GOODFELLAS), this prequel to Academy Award Nominee Christopher Nolan's THE DARK KNIGHT will explore how the Clown Prince of Crime came to be.
Yes, you read that right: Scorsese's Joker is actually part of Nolan's Dark Knight universe. This had been rumored in film circles for the past couple of months, but no confirmation had been found until now. It's worth pointing out – albeit of lesser importance – that this synopsis would seem to confirm that the film will be lifting heavily from The Killing Joke; “one bad day” is at the center of the Joker's manic ramblings.

This news is sure to be controversial in DC fans circles and beyond. One of the most beloved elements of Heath Ledger's Joker is his “multiple choice” origin, with each telling mixing up how he got his disfiguring facial scars (while one popular fan theory suggests he was an Iraq vet, fitting of The Dark Knight's 2000s setting). This origin film would by design provide a definitive solution. It is possible that – in keeping with The Killing Joke – Phillips will choose to present this simple as one dramatized possibility, although nothing official suggests that.

Besides unearthing mysteries, there's a more ethical debate. It had been assumed Ledger's Joker had been put to rest following the actor's untimely death before the release of The Dark Knight – he wasn't even alluded to in The Dark Knight Rises – putting extreme pressure on the filmmakers and whoever is eventually cast in the role.

Speaking of the filmmakers, despite the actual new being buried in a slate sent around the industry – not direct to press – Phillips has responded to the subsequent leak on his Facebook page. Curiously, he makes no mention of casting:

“There have been many iterations of the Joker in his 72-year history, but none have been as iconic or defining as Heath Ledger's Oscar-winning portrayal of the character in The Dark Knight. He captured the imagination of moviegoers with his manic psychosis and unclear past. I am incredibly privileged to be able to explore that history and provide the definitive backstory to one of cinemas greatest icons. We want to do the best to ensure the legacy of Heath and his performance while crafting something surprising for fans of the Clown Prince.”

It's interesting that there's no mention of Phoenix. He has been coy in interviews – as is fitting of actors in negotiations, believed to be added proof he is in the running – yet doesn't seem to be an ideal fit for the Joker presented in the synopsis. The actor is 43 years old, whereas Ledger was only 28 when he played the character, creating something of an inherent timeline issue; assuming Phoenix is playing his own age, the Joker would be in his 60s by the time of The Dark Knight's 2008. It's possible that this will be explored in the movie itself, or the connection is intended to be looser than the synopsis suggests. Of course, it's most likely that Phoenix isn't actually in consideration for the role itself. Whoever is playing the part, expect casting soon as the Joker origin is set to start filming in May .

What this development does mean is that we could see other characters from The Dark Knight Trilogy appear. Gary Oldman's Commissioner Gordon is possible, as is Tom Wilkinson's Carmine Falcone and Richard Brake's Joe Chill, and there's an outside chance – depending on the timeline – of Linus Roache and Sarah Stewart as Thomas and Martha Wayne, respectively. All actors would need deaging of some sort, but it would allow for some genuine cohesion between this movie and the “original” trilogy.

It also reveals that DC Films isn't afraid of returning to presumed “dead” continuities alongside the still-expanding DCEU (which still has Jared Leto as its resident Mr. J). If we're going to be learning Ledger's Joker's origin, what's to stop a sequel to The Dark Knight Rises with Joseph Gordon-Levitt or Batman Beyond featuring Michael Keaton?

All we know for now is that WB is so serious about the Joker origin, to the point they're staking the reputation of one of the greatest superhero movies of all time on it. Let's just hope it's more The Godfather Part II than Hannibal Rising.

Christopher Nolan declined to comment