Two years after the events of Batman: Curse of the White Knight, Azrael has wiped out Gotham’s criminals, Jack Napier is dead, and Bruce Wayne is in prison. As new villains arise, Harley must confront her own past with The Joker and Batman while helping the GCPD and an eager FBI agent uncover the truth behind a series of murders!

Spinning out of the runaway hit Batman: Beyond the White Knight comes an unforgettable coming-of-age super villain tale starring the children of Harley Quinn and The Joker! When the rebellious twins run away in a stolen Batmobile, only Joker Jack Napier's quickly fading hologram has any hope of getting them home safely and keeping them out of the family business. But a life of crime isn't the only temptation they are facing: the kids uncover a dark secret that could bring their dad back to life for good!