Continuity Note: This story takes place after Action Comics (2011) #8.
*The secrets of the 'missing five years' between when Clark Kent came to Metropolis and the present day continue to be revealed! In the wake of Brainiac's attack on Metropolis, Superman faces his first Earth-born villain: the Kryptonite Man! *Source: dccomics.com
Backup story featuring the origin of the Atomic Skull.