After splitting with the Joker, Harley Quinn joins superheroines Black Canary, Huntress, and Renee Montoya to save a young girl from an evil crime lord.
Batman discovers a mysterious teen-aged girl with super-human powers and a connection to Superman. When the girl comes to the attention of Darkseid, the evil overlord of Apokolips, events take a decidedly dangerous turn.
As Batman hunts for the escaped Joker, the Clown Prince of Crime attacks the Gordon family to prove a diabolical point mirroring his own fall into madness.