Batman: Dark Knight, Dark City

Plot

Collects Batman (1940-2011) #452-454 and Detective Comics (1937-2011) #629-633. Cover by Mike Mignola & George Pratt.

Batman is led through an urban labyrinth by the Riddler, who seems to have become a monster determined to drive Batman insane. In his quest, the Riddler is working with an occultist who has summoned a demon to stop Batman - but in the process, the Riddler himself is slowly changing into a nightmarish beast!