A four issue crossover between the four Superman titles. Superman, dressed all in black, is being held in Arkham Asylum by warden Solomon Grundy! He knows in his heart he can't be a criminal, so what is going on in this topsy-turvy world?
This story arc leads directly into "The Reign of Emperor Joker" story arc. Note that Emperor Joker #1 is the bridge between the two story arcs.