Before Krypton exploded and Jor-El put his baby son Kal-El in a rocket ship to Earth the benevolent ruler was forced to banish three irredeemable criminals to another dimension called The Phantom Zone. The trio's leader General Zod vowed revenge. Later of course Kal-El grew up to become Superman Earth's mighty champion. A battle with the criminal mastermind Lex Luthor ends with Superman hurling a nuclear warhead into space where it explodes but not harmlessly. Instead it frees the Kryptonian threesome from their other-dimensional prison. They soon discover they have almost unlimited power (the same powers in fact as Superman) which they use to take over the Earth. Meanwhile the intrepid reporter Lois Lane learns that her bumbling colleague Clark Kent is really Superman a revelation that leads to him bringing her to his frozen Fortress of Solitude and renouncing his powers in order to make love to her. It is only when Superman and Lois return to civilization that they learn of the three Kryptonians and how Lex Luthor has joined forces with them. Now Superman must reverse the irreversible and regain his powers in order to save mankind.