Warning: Contains SPOILERS for The Batman.
The Batman’s deleted scene offers a better look at Barry Keoghan's version of the Joker, but it also sets up the Joker's perfect Arkham escape plan. Not only does The Batman feature four major Batman villains - one being Catwoman in an anti-hero role- but it also introduces a brand-new Joker. While the final cut of the film did feature Batman’s most iconic villain in a brief moment with the Riddler, Matt Reeves had filmed a larger and more revealing scene involving the character.
In the deleted scene now released as part of a marketing campaign, Batman goes to the Joker, who’s locked in Arkham, in search of understanding more about the Riddler's modus operandi. In a very Silence of the Lambs style, Batman believes that the profiles of the Joker and that of the serial killer who is operating in Gotham are similar, although it is never made clear what crimes this version of the Joker committed before being arrested. The Joker does offer some thoughts on the Riddler's case, but it's Batman he really analyzes. This is exactly the reason the scene was deleted, as the Joker ended up spelling out the lesson that Bruce should only learn by the end of the movie: that Batman was only inspiring more violence with his current approach.
In addition to those interesting reflections on the characters, The Batman’s deleted scene also hints at plans for the Joker in the franchise. A small detail in the scene that may have gone unnoticed is that there was a paperclip in the files the Batman handed to Joker, but when Joker returned the files, the paperclip was no longer there. It’s a brief and small detail, but very revealing given the Joker’s track record of breaking out of Arkham in dozens of Batman stories. The Joker could use the paperclip to open a locker or even to manufacture a weapon, and that could make Batman’s mistake of not noticing the missing paperclip something that the hero will always regret. It is a deleted scene, so it's difficult to say whether it will be considered canon for future movies, but the paperclip detail proves that they were at least planning on setting up Joker's Arkham escape.
While plans for The Batman's sequels and spinoff shows are still a mystery, the fact that the Joker was already cast indicates that the character will have a significant role in the future in some way or another. If The Batman 2 sees the aftermath of the flood caused by the Riddler, then the movie could be an adaptation of No Man's Land and focus on how Batman's villains are taking advantage of all the chaos to achieve their goals. A moment of mayhem like that would be the perfect time for the Joker to escape from Arkham, and the return of the clown prince of crime amidst such a turbulent time for Gotham would make things even more difficult for the city and Batman.
The Batman’s deleted scene sets the tone for what this new version of the Joker will be like, and the paperclip detail indicates that he can become part of the story sooner than later. While it's always fun to see the villain and Batman having a conversation in Arkham, the Joker can cause much more problems once he’s out. Whether it’s in the Arkham spinoff or The Batman 2, the Joker will try to escape at some point – and Batman may have given him everything he needs.