As Green Arrow and Black Canary finally prepare to wed after a tempestuous on-and-off relationship, the World's Greatest Super-Villains � including Lex Luthor, The Joker, Gorilla Grodd, Cheetah, Poison Ivy, Dr. Light and more � stage an unprecedented attack on the JLA, taking Wonder Woman and others prisoner. It all leads to an epic melee as the titanic forces of good and evil collide!