However, Batman refuses to be apprehended until Scarecrow has been stopped, and locks Robin in a holding cell.The Arkham Knight activates the Cloudburst device, flooding Gotham City with fear toxin.Batman is also exposed to the toxin, which triggers a powerful hallucinogenic response.He receives a message from Scarecrow revealing that Barbara is in the same safehouse where Ivy was held, but before Batman can save her, Barbara is doused with fear toxin and shoots herself in the head.While most were cured, the patients who were not treated are starting to look and act like the Joker.
Harley Quinn has taken over the studios, planning to gather the mutated citizens and keep the Joker's legacy alive through them.
Nine months after the Joker's death, crime rates in Gotham City have dramatically declined, but Batman anticipates a new threat and maintains a vigil over the city.
Before his death, the Joker sent his mutated blood to Gotham's hospitals, and several patients were infected.
Batman and Gordon proceed to meet Scarecrow on the building's roof.
Gordon apologizes for his anger and says he has never forgotten how he met Bruce Wayne on the night of his parents' death, since he now knows Batman's identity.