Batman: City of Madness

"Buried deep beneath Gotham City there exists another Gotham. This Gotham Below is a living nightmare, populated by twisted mirrors of our Gotham's denizens, fueled by the fear and hatred flowing down from above. For decades, the doorway between the cities has been sealed and heavily guarded by the Court of Owls. But now the door swings wide, and the twisted version of the Dark Knight has escaped...to trap and train a Robin of his own. Batman must form an uneasy alliance with the Court and its deadly allies to stop him - and to hold back the wave of twisted super-villains, nightmarish versions of his own nemeses, each one worse than the last, that's spilling into his streets!"--