This episode elaborates upon the secret government conspiracy against the Justice League, introduced in such third-season episodes as "Fearful Symmetry" and "Ultimatum." As Batman tries to halt the conspiracy that has been fomented by the sinister Amanda Waller, Superman heads into the bowels of a volcano for a titanic battle from which he may not emerge alive. It seems that Superman's opponent is the diabolical Doomsday -- who was supposed to have been permanently killed off several episodes ago. ~ Rovi