If the 2019 film Joker built the myth of Arthur Fleck (Joaquin Phoenix) as Joker, its sequel, Joker: Folie à Deux, categorically deconstructs it. When the film opens, Arthur is being held in Arkham for the murders of Murray Franklin and several others. He seems to be a very different man than the one we saw at the end of the first film when he murdered Murray. Things change when he meets Harleen “Lee” Quinzel (Lady Gaga), another patient at Arkham, who brings out the Joker persona as Arthur faces trial for his crimes and the prospect of a death sentence. This is all that happens at the end of Joker 2.

Yes, Arthur dies at the end of Joker: Folie à Deux.

After killing Murray on live television in the first film, Arthur, as Joker, has become a symbol of anarchy and violence for certain segments of Gotham City's population, so much so that these people fervently believe that there will be no distinction between Arthur and Joker from now on. This is also what the prosecution, led by newly appointed Assistant District Attorney Harvey Dent (Harry Lawtey), intends to prove at trial. Conversely, Arthur's defense team intends to prove that he and Joker are separate entities trapped in one body.

After Lee comes into his life, Arthur tries to embrace Joker, while simultaneously fearing that part of him and decides to put on a show at his trial, complete with his clown makeup, for her and the audience. Eventually, however, he accepts that he killed those people and admits to strangling his mother to death, but not in the way Lee and his followers had hoped. In his testimony, Arthur emphasizes his averageness and comes across as a victim of a cruel and uncaring society.