DETECTIVE COMICS #870
The battle lines have been drawn. The insane Impostor Joker will lead his army of Jokerz against the imposing Impostor Batman and his Guardian Bats – and the battleground will be the Gotham City World's Fair. The only hope Gotham has is The Dark Knight himself, but can even Batman stop both Impostors before more blood is shed? All will be revealed, including the mystery behind the Impostors, in this shocking and horrifying conclusion to "Batman: Impostors"!