Following the recent capture of an individual (dubbed “The Rookie”) who had broken into the laboratory of Professor Ivo, Commissioner Gordon oversees their transfer to Stryker’s Island in Metropolis. Enlisting the aid of the incarcerated Lex Luthor, Gordon reveals that the Rookie gained the ability to absorb superpowers, based on the secret Amazo Project, and offers Luthor a reduction in his prison sentence in exchange for monitoring the new villain’s powers. Before Luthor agrees, his personal bodyguard Mercy Graves arrives and helps to break him and the Rookie out, alongside a number of other villains in the prison including Cheetah, Solomon Grundy, and Metallo. As they prepare to make their escape, the Justice League arrives to intercept them. Meanwhile, The Joker and Harley Quinn break in to Wayne Tech, stealing several items including a mysterious box, but are forced to escape from Batman. Reunited with Luthor’s band of villains, the group find themselves defeated by another superhero team from a parallel Earth, called the “Justice Syndicate” as the Rookie and Cheetah escape. Following their swift victory, the Syndicate promptly warp the Justice League away, which Harley witnesses before being forced to escape with Luthor and Joker.