2019's Joker 2's working title, Joker: Folie á Deux, which is French and translates to "madness for two."

Unsurprisingly, fans have speculated about what that title could mean ever since it was revealed, and there are a ton of possibilities, but some are more realistic than others. Regardless of whether they're logical theories or ones that are more like fans' fever dreams than anything, Redditors have gotten creative.

Son Of Joker

Harley Quinn Reuinted With Joker Son

It's extremely unlikely, but MySockHurts pulls a deep cut from the comic books, asking, "So we're getting a Son of Joker movie?" The story arc that the Redditor is referring to isn't exactly Batman's answer to Son of the Mask, the family-friendly sequel to the Jim Carrey classic, but one of the darkest narratives in Joker's history.

In Old Lady Harley, Harley Quinn gives birth to her and Joker's son, but she abandoned him out of shame. Junior grew up resenting his mother, and then intentionally scarred and disfigured his own face in a bid to look more like his father. It's hard to see the narrative as the focus for Joker 2, as it leapfrogs over some key points, such as Harley's place in the universe, but given the movie's mysterious title, it's a possibility even if it is farfetched. The creation of Joker Jr. was also the narrative of Batman Beyond: Return of the Joker, but that'd be even harder to implement into the sequel.

Harley Quinn's Introduction

Harley Quinn kicking Batman in Batman The Animated Series

Though they seem just as confused as everyone else, Captainhowdy82 points to the most obvious possibility, asking, "So is the other person Harley Quinn?" There are some clues that lead to this being the case. The most cryptic clue is the color scheme of the Joker 2 screenplay cover, which is red and black, just like Harley's costume.

The other reason why Harley could be the character that the title is hinting at is a little more obvious. At the end of Joker, Arthur is locked up in Arkham Asylum, which is where the Joker first meets Harley in actors who could play Harley Quinn.

ing Of The Torch

Willem Dafoe Joker Fan Art

There have been so many storylines both in the comic books, animated series, and movies about copycat Jokers, and TheCatsTrailerRuled thinks that's what the subtitle is referring to. It's a popular opinion, and many other s have different ideas on how it could be approached.

The Redditor has an interesting theory, explaining, "Maybe it's about the consequences of Joker's decisions eventually leading to someone else who is smarter than him to take on the mantle of the Joker, and he dies at the end of the movie." That makes perfect sense, as Arthur doesn't have the wits that the iconic character traditionally has. Not only that, but the end of Joker saw so many Gotham citizens influenced by the idea of the Joker that it'd be poetic if Arthur created his killer.

There Won't Be Two Jokers, But Three

The three different Jokers in the Three Jokers comic miniseries.

The title might have influenced a ton of theories about the possibility of two Jokers, but StefanMorse takes the theory even further, speculating that there might be three Jokers. The Redditor posits, "There was a comic book where there were three Jokers, so it could be based off that…"

The Redditor is referring to 3 Jokers, one of the best versions of the Joker in the comics, which follows Batman trying to solve Joker-influenced crimes happening across Gotham, but they're all happening at the same time. Even though the sequel's subtitle literally translates to Madness of Two, Phillips could be trying to throw fans off the scent, or a third Joker could be a surprise midway through the sequel.

It'll Be A Multiverse Of Madness

Joker with a bat looking serious in Suicide Squad

Based on the movie's working title, Doctor Strange in the Multiverse of Madness, and the Redditor thinks that could be the case for the Joker sequel too.

That would be great to see, and given that every movie released this year is seemingly about a multiverse, it'd hardly be surprising if this idea was discussed by executives over at Warner Bros. However, based on the world that Phillips built, which is completely grounded in reality, the chances of a multiverse in the Joker series are slim to none. And some fans are still trying to forget that Leto's portrayal of the character ever happened.

Batman Will Be More Present

Arthur puts his fingers in Bruce Wayne’s mouth in Joker

While most Redditors make some bold claims, there are three proper possibilities that the title could be hinting at. One is Harley Quinn, the second is another Joker, and the third is the Caped Crusader himself. Jurble puts it best, positing, "I'm gonna venture a less popular guess and say the second man will be Batman, with them playing the angle that he has to be crazy to do what he does."

However, in one of the creepiest scenes in the movie, Joker saw Bruce Wayne as a child, so it's hard to understand how a showdown between the two would work unless it's set a decade or two in the future. But there's no reason why Joker 2 can't be set ten years later, and it'd be fascinating to see Phillips' unique depiction of Gotham in the 1990s.

It'll Have An Arkham Setting

Arthur running in Arkham Asylum in Joker

Taking the concept of Harley Quinn's introduction even further, Schering thinks that because the name hints at Joker's sidekick, the whole movie could be set in Arkham Asylum. The Redditor thinks "it's all set in Arkham Asylum and gets real creepy," which sounds like an amazing horror movie.

Batman movies have been Taxi Driver.

NEXT: 10 Best Twitter Reactions To The Joker 2 Announcement