A few years after learning of his origins, Clark Kent lives in Metropolis as a reporter for The Daily Planet, while using his superpowers for good as the hero Superman. While Clark finds himself drawn close to his fellow colleague Lois Lane as Superman, he also finds himself dealing with escaped terrorist John Corben, who wreaks havoc with a robotic suit stolen from billionaire Lex Luthor. Meanwhile, an alien ship comes across a Kryptonian satellite, unaware that Brainiac is hidden within its mainframe.

During the opening of a museum, Superman tries to stop two robbers. He fails when he falls victim to the poisoning effects of Kryptonite, one of the exhibited rocks. Lex Luthor sees the surveillance tape of the event and determines that this must be Superman's one and only weakness. Luthor orchestrates a scheme to trap Superman, place him in vicinity of the rock, and put an end to him once and for all.