LexCorp and John Henry Irons design a powerful prototype armor suit for the Metropolis SCU, which Lex hopes will make Superman's services unneeded. The SCU officer who pilots the suit, Sergeant Mills, proves a useful partner to Superman at first, but the suit soon corrupts the officer's mind, making him violently unstable. Irons is discouraged over the failure of his project, but Superman convinces him that it would be a valuable tool if Irons can find a way to stabilize it.

John Henry Irons, an ex-employee of LexCorp, has lately been developing a new, advanced suit for himself. When Superman is caught off guard from the reappearance of Metallo, Irons must suit-up as Steel to help the Man of Steel.