Joker 2 Theory: Harley Quinn Isn't Who You Think She Is

Arthur Fleck (Joaquin Phoenix) is back in the "Joker: Folie à Deux" trailer, which is hiding so many details already. The big question between the winks to the previous film — which gave us Phoenix's Oscar-winning performance and landmarks in Batman history — is how Joker will meet Harleen Quinzel, aka Harley Quinn (Lady Gaga), in Todd Phillips' brutal and alternative take on the iconic character. There's no clarification on just how Harley gets caught up in Joker's orbit from what's on show so far. From choir girl to potential partner in crime, the origins of Harley remain unknown, sparking suggestions that what we're seeing is a twisted view of Harley from Arthur that isn't the reality he's refusing to accept.

Given just how fractured Fleck's mind becomes by the end of the first film and how well-known Joker is for being out of control, it's a possibility that Phillips' iteration of the character could be seeing Harleen in a different light than everyone else. Gaga's character could very well be a doctor like she was in the comics before being corrupted by Joker, or perhaps another patient struggling with mental illness that Fleck paints in a romantic light. It's a similar idea to the theory regarding Fleck's view of Zazie Beetz's character in "Joker," which even led the film's director to reveal her fate. Then again, there could be a different kind of trick that Arthur could be playing on his own mind, and Harley might not exist at all.

While there's every chance that Harley might well be a good-hearted doctor trying to get through to Arthur and failing, other evidence might suggest that she is entirely a fabrication made up by Fleck as a bit of escapism from the situation he's found himself in. It would explain why there are shifts between the real world and the big song-and-dance numbers that the film is teasing. Like Tyler Durden (Brad Pitt) was to the Narrator (Edward Norton) in "Fight Club" (aka the film we're not supposed to talk about), Harley could be Arthur's inner thoughts breaking out and sending him into this new chapter as the Clown Prince of Crime.

It would mark an interesting shift from the previous film, which kept Arthur fighting through the ugly world Phillips had created until he got his last laugh, but there's also the chance that there could be a far more accurate and just as unsettling origin to his new love. Harley could be another fan following in the literal footsteps of Arthur, idolizing this anarchist who hides behind face paint and a red and yellow suit, even going as far as visiting him in prison, leading to the lipstick scene in the trailer that has everyone losing it. We'll see for ourselves when "Joker: Folie à Deux" arrives in theaters on October 4.