Set after the events of Superman II, Joker, having survived the events of The Batman, has made his way to Metropolis, alongside his girlfriend and accomplice Harley Quinn, where he successfully steals a Kryptonite statue and strikes a deal with billionaire Lex Luthor to kill his hated arch-nemesis Superman in exchange for both the death of Batman and $1 billion.
Meanwhile, Batman, having learned of the Joker's return, has successfully tracked him to his current location, leading to a showdown between the caped crusader and the man of steel himself Superman where, despite their differences, they must work together to stop both Luthor and the Joker, especially when it turns out that the Joker has kidnapped Superman’s love interest Lois Lane.
