Folie à Deux,” Lady Gaga will introduce audiences to Lee Quinzel, her version of the Joker’s love interest Harley Quinn from the DC comic books.

Joker: Folie à Deux pairs 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 to Joker: Folie à Deux's cast,

Let's get the elephant-in-clown-makeup in the room out of the way first: Arthur dies at the end of Joker: Folie a Deux, meaning a third movie following the titular clown is very unlikely, if not impossible (unless they decide to go full surreal dream sequence on his deathbed, or a similarly 'out there' premise).