Find Commissioner Gordon & company in the midst of a firefight at the Gotham Botanical Gardens. Gas masks soon prove useless against a toxin that not only permeates the surrounding air but, thanks to a hail of poisoned darts, penetrates body armor as well. As sanity begins to slip from Gotham's finest, the World's Greatest Detective himself has already crossed the threshold into madness. Up on the roof of the Museum of Fine Arts, the newly scratched Batman writhes in the throes of psychosis while Catwoman looks on, coming to the terrible realization that her claws had been tainted with toxin. In a nearby alley, a maestro of fright wields both a scythe and a master plan. The Dark Knight is right where Scarecrow wants him: in the dark. Batman, meet the abyss.