The Joker's army of superpowered villains has escaped to spread their insanity across the globe. Enter the JLA — but can even the World's Greatest Heroes really hope to contain, let alone stop, the mayhem? Meanwhile, the Joker decides that there's more to life than body counts, and starts planning a legacy that will change the world forever.
The JLA return to Earth to discover a world gone mad, the chaos being caused by the Joker's final mad fling, his attempt to go out with a bang. Batman and Nightwing scour every one of his known hideouts in Gotham, but the Joker and his newfound pals are currently on Easter Island, cooking up various dastardly schemes, which, to the Joker's mind, tend to lack the grand flair of originality. Lex Luthor and his cabinet meet to discuss a response to the situation, while Oracle sends out Spoiler and Batgirl, and eventually Power Girl, to rescue Harley Quinn - the Joker wants to capture her so that she can carry his child. Oracle's relationship with Nightwing is under serious strain, particularly as she talks seriously about killing the Joker, setting aside their rules just this once.