Warning! This article contains spoilers for Joker: Folie à Deux.
Joker: Folie à Deuxpairs Joaquin Phoenix’s Arthur Fleck with Lady Gaga’s Harley Quinn, providing an intriguing backstory and questionable motives for the latter by the film’s conclusion. Gaga is undoubtedly the biggest addition toJoker: Folie à Deux’s cast, bringing to life the iconic partner of Joker from DC Comics. However, like 2019’sJokertreated its main character, the sequel gives Harley Quinn a much more grounded, realistic, believable take that strips most of the exaggerated elements of the source material from the character by the time ofJoker 2’s climactic ending.
Although there areDC Easter eggs found inJoker 2that reference Harley Quinn’s backstory and iconic make-up, many elements are left purposefully unclear about her character when the credits roll. This ties into the overall journey of Arthur Fleck, as the character navigates a new relationship amid court trials, abusive Arkham guards, lies, and deceptions. Thepotential story ofJoker 3could further flesh out Harley Quinn, deepening her backstory and motives fromJoker: Folie à Deux.

Harley Quinn’s Two Backstories Explained - Which One Is Real?
Harley’s Lies Cast An Uncertain Shroud Over Her Past
In only Harley Quinn’s second scene inJoker 2, she reveals her backstory to Arthur Fleck. She explains that she is a less-fortunate citizen of Gotham from Arthur’s neighborhood and that set fire to her parents' apartment and burned down the building. Harley, named Lee throughout the film, states that this led her mother to commit her to Arkham Asylum, also revealing that her father was abusive and that he died in a car crash shortly after the fire.
However, later in the film,Arthur’s lawyer Maryanne explains that Harley has been playing him. Maryanne reveals that Lee is actually from the wealthy Upper East Side of Gotham and that she was a psychiatry student. Fleck learns that Lee never burned down an apartment building and that both of her parents are alive. Finally, Maryanne states that Lee was never committed to Arkham, but instead voluntarily turned herself in to get closer to Arthur and was free to leave whenever she pleased.

Harley Quinn being depicted as a psychiatry student links to her comic book origins, in which she initially treats Joker before joining him.
Naturally, the opposing backstories of Lee inJoker: Folie à Deuxlead to the question of which is real. Later in the movie, Arthur confronts Lee, and she reveals she told him partial lies, but that most of what Maryanne said is truthful. As a result,it is safe to assume Lee’s backstory revealed by Maryanne is what is real, raising into question the former’s motives for entering Arkhamand manipulating Arthur.

Harley Quinn’s Motive In Joker 2 Explained
Lee Is A Personification Of Those Who Idolize The Joker Persona
By the time ofJoker: Folie à Deux’s ending, it is not outwardly spelled out exactly what Lee was looking to achieve in the film.The only constant throughout the story is that Lee wishes to bring out the Joker personaof Arthur for good. Lee believes that Arthur does not have a dissociative identity disorder as his lawyers and doctors claim, but that Arthur and Joker are one and the same and the latter is the real person, not a mask or coping mechanism.
Therefore, many of Lee’s motives can be placed down to this. By lying to Arthur and stoking the more violent tendencies within him, it is likely that Lee sought to “awaken” Joker completely. Why exactlyLady Gaga’s Harley Quinnwishes to achieve this is a topic of debate, but it could link to her own mad tendencies paired with the former interest in psychiatry she was confirmed to have. Above all else, though,Lee’s motive inJoker 2stems from love and idolization.

Joker: Folie A Deux’s 10 Biggest Spoilers
Joker: Folie à Deux features some of the most shocking twists in DC’s live-action history, though Arthur Fleck’s perspective is still unreliable.
The firstJokermovie raised many difficult, controversial arguments over whether Arthur was justified throughout the story. Both in-universe and in real life, the idea that Joker was justified has been argued. In the former, Joker was shown to gain many followers who used the persona as a way to justify violence, aggression, and murder. InJoker 2, Lee is a personification of this. Lee falls in love with this idea as much as its figurehead, explaining her motives for wanting to bury Arthur and unleash Joker.

Why Harley Quinn Leaves The Courtroom At The End Of Joker 2
Lee’s Ending Reflects Her Love For Joker & Lack Thereof For Arthur
ThroughoutJoker: Folie à Deux, it becomes clear that Lee is in love with Joker. At multiple points, notably when Arthur is showing his Joker tendencies, the two are intimate with one another. Lee’s primary reason for wishing to unlock Joker completely is that she idolizes him and is in love with him. With that in mind, it becomes clear why Lee leaves Arthur in the courtroom at the end ofJoker: Folie à Deux.
Once Arthur acknowledged that Joker was not the real him, Lee’s object of idolization was killed and she left…

Arthur admits to the court that Joker was a personality crafted by him to avoid his trauma and unleash his violent fantasies. This visibly upsets Lee, who storms out of the courtroom and ignores Arthur’s call afterward. The reason for this is that it was Joker whom Lee was in love with, not Arthur. Once Arthur acknowledged that Joker was not the real him, Lee’s object of idolization was killed and she left.
What Happens To Harley Quinn After Joker 2
Harley Quinn’s Fate Is Left Admittedly Unclear
At the end ofJoker 2, Harley leaves Arthur to be arrested and returned to Arkham. After this, Lee is not seen again, yet the film gives some hints at what could have happened to her. Before this scene, Arthur tries to call Lee before his verdict is given. She listens to his voicemail while pointing a gun at her head. This could indicate that Lee faces death by suicide afterJoker 2’s DC timelineconcludes, driven by the “death” of the man she loved, Joker.
Another possibility is that Lee moves onto another person as the object of her obsessions. AsJoker 2’s ending proves, there are many more people in Gotham who idolize Joker and want to be like him. Above all else, the other inmate in Arkham who kills Arthur and cuts a smile into his face as the movie ends could become theJokeruniverse’s titular character. If Lee enters Arkham once more, she could find him and they could become more akin to the DC Comics version of Harley Quinn and the Crown Prince of Crime.
The REAL Joker In Joker 2 Explained
Joker: Folie A Deux continues the story of Joaquin Phoenix’s Arthur Fleck, but the movie introduces another key character who becomes a second Joker.
While this is unlikely to be shown given director Todd Phillips' unwillingness to return to the franchise, this could be the off-screen ending for Lee. Overall, Harley Quinn’s ending inJoker: Folie à Deuxis as intentionally uncertain as her motives and backstory throughout the movie. This could pave the way for a Harley Quinn spin-off ofJoker 2, or simply end this section of the DC Universe in a way that is open to interpretation, as much of Arthur Fleck’s story has been.
Joker: Folie a Deux
Cast
Joker: Folie à Deux is the sequel to Todd Phillips' critically acclaimed comic book thriller Joker. Reprising his Academy Award-winning performance as the failed comedian Arthur Fleck, Joaquin Phoenix revisits the iconic DC character alongside Lady Gaga, who makes her debut as Joker’s lover Harley Quinn in this standalone continuity of the DC Universe.