Superman Zero hour

"Time is collapsing in on itself. The villainous Extant has ushered in a series of black holes that are swallowing the universe--past, present and future! Superman, like everyone else in the DC Universe, has seen time loops affect his life. The result? Krypton never exploded. The Kents never found a baby Kal-El in a field. Superman isn't the protector of Metropolis. Then, after the crisis in time has been averted, new details about the origins of Superman, Superboy and Steel are revealed."--