“Folie à Deux” does neither. Taking a cue from the last scene of “Joker” — a psych evaluation where Arthur hears Frank Sinatra’s “That’s Life” in his head and starts to sing along — the film is basically one long drawn-out courtroom drama, interrupted by musical numbers (old standards, most of them sung in Arthur’s head).

The ending of the film (spoilers ahead) is one of the most universally disliked aspects of Joker: Folie a Deux, a miserable end for Arthur Fleck and the alleged birth

Instead of stigmatizing mental illness, "Joker: Folie à Deux" becomes a meditation on what mental illnesses can reveal about our societies.