"An armed robbery carried out by gunmen dressed as Batman. A string of similar-looking corpses turning up in morgues ... then disappearing. An experiment gone dangerously awry, carried out in Bruce Wayne's own tower. Somehow, all of these mysteries are tied together, orchestrated by a terrifying killer known as Mr. Toxic, and Gotham City's fate--and the world's--is on the line. Can the Dark Knight piece together the mystery, while also dealing with a gang of fear-gassing Scarecrows, an attack on Arkham Asylum by the Court of Owls and the escape of one of Arkham's most dangerous inmates--the hypnotic Black Mask?"--Provided by publisher.