After discovery a crashed space ship and deriving a serum from the dead corpse, the U.S. Army develops a serum they hope will turn the tide of battle in World War II. Their first subject is a 4-F Volunteer Clark Kent, which proves to be a success. Granted the abilities of flight, super strength, heat vision, and much more, Kent accepts the mantle of Super Soldier and with his partner, Jimmy Olsen reporting on the news of his exploits he battles the Nazis and paves the way to victory until the Third Reich unleashes their newest weapon, Ultra-Metallo, and after a battle over the Atlantic, both fighters plunge into the icy cold depths.
Years later, a now much older Jimmy Olsen is kidnapped by the evil Hydra and their leader the Green Skull, who once was known as Lex Luthor. The Green Skull learns of Super Soldier's reappearance and growing weakness and resurrects the Ultra-Metallo to crush the soldier once and for all.
Jimmy escapes and manages to warn Clark of the impending threat, and without a moment hesitiation, Super Soldier flies into battle across Washington DC against his metal opponent. During their fight, Luthor taunts the Soldier through a speaker on Metallo and reveals the secret behind the Soldier's growing weakness. Fallout from the K-Bomb Luthor developed to end the war covers the entire earth, but it's radiation effects only one man, Super Soldier. It also powers Ultra-Matallo.
Super Soldier is able to overcome his foe by discovering that lead shields him from the deadly K-radiation, and is able to power down Ultra-Matallo once and for all, while at the same time exposing Luthor for what he is.