Batman: Arkham Knight On Halloween, Scarecrow forces the civilian evacuation of Gotham City after threatening to unleash his potent new fear toxin. Batman tracks Scarecrow to a hideout where he rescues the imprisoned Poison Ivy, who had refused to join Batman's other rogues in Scarecrow's plot. Batman meets with Oracle, who identifies Ace Chemicals as the source of Scarecrow's toxin. Release Date:June 2015Genre:Action Adventure, Open WorldDeveloped By:Rocksteady GamesPublisher:Warner Bros. Interactive Entertainment Latest News See All News No items found. Latest Images See All Images No items found. Latest Videos See All Videos No items found.