“Joker: Folie à Deux” is a chaotic,  cult-classic sequel to 2019’s Joker

Arthur Fleck isn’t the real Joker;  the real one is revealed later. 

Arthur and Joker have split personalities, both can’t exist together. 

Lady Gaga plays Lee, who loves Joker’s fame, but not Arthur. 

Lee isn't Arthur's "folie à deux"; she  might like the real Joker instead. 

The real Joker is an Arkham inmate  who kills Arthur. 

Arthur's death completes a two-part origin story for the true Joker. 

There are hints at more Joker villains, including Harvey Dent (Two-Face). 

Director Todd Phillips may not  return for a Joker 3

The film questions the blurred lines between entertainment and reality.