After meeting Dr. Harleen Quinzel, Jason Todd manages to break out of Arkham Asylum with her help, however, during their attempt, their vehicle crashes into a vat of acid at ace chemicals. Bleaching his skin and driving him insane, he adopts the identity of the Joker, working alongside his love interest, now known as Harley Quinn. However, they must survive the efforts of Amanda Waller’s task force X who sends an unstoppable mercenary to bring them in.