Computer programmer Gus Gorman (Richard Pryor) is hired by financial tycoon Ross Webster (Robert Vaughn) to seize control of a weather satellite and annihilate Colombia's coffee crop. When Superman (Christopher Reeve) manages to thwart the plan, Webster commands Gorman to use the satellite to locate kryptonite, the Man of Steel's mortal weakness. But a missing unknown element in the kryptonite -- replaced by Gorman with tar -- causes an unintended side effect when presented to Superman.
Just before the destruction of the planet Krypton, scientist Jor-El (Marlon Brando) sends his infant son Kal-El on a spaceship to Earth. Raised by kindly farmers Jonathan (Glenn Ford) and Martha Kent (Phyllis Thaxter), young Clark (Christopher Reeve) discovers the source of his superhuman powers and moves to Metropolis to fight evil. As Superman, he battles the villainous Lex Luthor (Gene Hackman), while, as novice reporter Clark Kent, he attempts to woo co-worker Lois Lane (Margot Kidder).
Superman (Christopher Reeve) foils the plot of terrorists by hurtling their nuclear device into outer space, but the bomb's shock waves free the Kryptonian villain General Zod (Terence Stamp) and his henchmen Ursa (Sarah Douglas) and Non (Jack O'Halloran) from their imprisonment. Traveling to Earth, they threaten the planet with destruction at the same time that Superman decides to renounce his superpowers in order to live a normal life as Clark Kent with his new love, Lois Lane (Margot Kidder).
Computer programmer Gus Gorman (Richard Pryor) is hired by financial tycoon Ross Webster (Robert Vaughn) to seize control of a weather satellite and annihilate Colombia's coffee crop. When Superman (Christopher Reeve) manages to thwart the plan, Webster commands Gorman to use the satellite to locate kryptonite, the Man of Steel's mortal weakness. But a missing unknown element in the kryptonite -- replaced by Gorman with tar -- causes an unintended side effect when presented to Superman.