$1 billion worldwide and earned 12 Oscar nominations, with Joaquin Phoenix winning his first Oscar for his performance as struggling comedian Arthur Fleck, aka The Joker.“Folie a Deux” roughly translates to “shared madness,” which may be a comment on how the Joker tapped into the boiling rage in Gotham City over its growing inequality, leading to the original film’s dramatic climax in which Batman’s future arch nemesis dances on top of a police car as a rioting crowd cheers him on.While specific plot details haven’t been unveiled, much of the film is expected to take place within Arkham Asylum after Phoenix’s Arthur Fleck has been sent there following the events of the prior film, and it is even expected to have musical elements throughout.Keener was most recently seen in Netflix’s “The Adam Project” opposite Ryan Reynolds and Mark Ruffalo.