What happens when the Dark Knight and the Man of Steel wake up on a skull-shaped planetoid packed full of cybernetic versions of their entire rogues galleries? Figure out why they’re being worshipped like gods, that’s what! What is this strange new Brainiac’s endgame—and how did Batman and Superman’s own villain database mutate into this twisted, metallic death planet? The mystery deepens as our heroes’ allies desperately search for their missing comrades...