Based upon the narrative structure of the first Joker movie starring Joaquin Phoenix, a new theory helps explain why Joker: Folie à Deux will be a musical with Lady Gaga's Harley Quinn. In the first film from director Todd Phillips, Arthur Fleck's disturbing evolution into the Joker is revealed, though not every event that happens to the future Clown Prince of Crime is real. As such, the musical elements and romance promised for Joker 2 could follow a similar path.
Joker: Folie à Deux is set to be a romantic musical with the addition of Lady Gaga as Harley Quinn. As such, it seems the sequel will be inspired by Joker and Harley's romance first seen in Batman: The Animated Series before Harley was brought into the comics' DC Universe. Beginning her origins as a psychiatrist at Arkham Asylum who becomes infatuated with the Joker, it's possible the upcoming sequel could follow a similar origin considering Fleck was institutionalized in Arkham State Hospital at the end of Joker. However, Harley's attraction to Arthur could mirror Fleck's own flawed grasp on reality.
Arthur Fleck Was An Unreliable Narrator In Joker
By the end of the first Joker, it's not clear what is to be believed about Arthur Fleck's evolution into such a controversial public figure, a murderer who managed to gain a following and cause a mass riot after having resonated with the disenfranchised and those long ostracized in Gotham City. Although Arthur had seemingly begun a relationship with Zazie Beetz's Sophie prior to his full transformation, it was later revealed that the majority of their time together was merely a figment of Arthur's imagination. As such, it calls into question nearly everything about Arthur's story.
Essentially, it's unknown whether Arthur imagined the entire movie's narrative as one dark joke during his incarceration in Arkham or if he was put in Arkham following an actual riot he started as the Joker. As such, Arthur Fleck is the definition of an unreliable narrator. Keeping that in mind, this could be how Lady Gaga enters the picture along with the sequel's musical elements and romance.
Will Lady Gaga's Harley Quinn Lead Joker 2's Story?
As a dynamic theory for Joker: Folie à Deux, it's possible that Lady Gaga's Harley Quinn could serve as the primary protagonist rather than Arthur Fleck himself. Not only would this help confirm what was real from the first Joker, but it would also offer a brand-new character whose mind may be just as troubled. Not unlike the scores of admirers some high-profile criminals gain following their incarcerations, Harley could become similarly attracted to the Joker even if she isn't a psychiatrist as she was in the comics. His reputation and infamy could be enough for Gaga's Harley to develop a one-sided romance even if she's never met him in real life.
Just as Fleck and his disturbed mind served as Joker's unreliable narrator, Harley can be the sequel's narrator, with audiences experiencing the narrative and events as she does in her own mind (whether they're real or not). As such, romantic fantasies of being with Joker could be how the musical elements come into play, as they'll all be within her head. However, that doesn't mean that Harley and Joker won't eventually collide in real-life (it just might not live up to the potentially fabricated romance within Harley's mind).
Harley's Damaged Psyche Can Explain Joker's 2's Musical And Romance
While largely conjecture, the first Joker does provide a precedent for a relationship not being what it seems in reality. Likewise, the musical and large portions of the romance being in Harley's head would be a natural way to incorporate them into Joker: Folie à Deux while also fitting past depictions of Harley in the earliest days of the character when she was hopelessly devoted to Joker very much to her own detriment. It's also a way in which Harley and Joker's relationship can be shown in an accurately negative and toxic light rather than being put up on a pedestal as something to be emulated.
