Laughing Man
Later on, the Laughing Man attacks Gotham City Police Headquarters to eliminate Casey Jones, but is confronted by the Turtles and Casey, who has had his memory and gear returned to him by April just in time. After the Turtles taunt him and show him the face of his new rival, the Laughing Man retreats. Batman contacts Commissioner Gordon through a hologram, thereby restoring the latter's memories, and relates his plan to lure the Laughing Man to Ace Chemicals - the place where the Joker was "born" - in order to restore his memories.