‘Joker: Folie à Deux’ Ending Explained: Who Stabs the Joker?

Image from Decider

• Joaquin Phoenix's Joker faces a surprise attack from an unexpected source in the film's explosive ending, setting the stage for a showdown with Lady Gaga's Harley Quinn in the highly-anticipated sequel
• Director Todd Phillips promises the stabbing will have major implications, hinting that the Joker may have finally met his match in the unhinged Harley – and that this power shift could reshape the entire Gotham landscape