Superman III

Superman II is a 1983 superhero film based on the DC Comics character of the same name.

Plot
Gus Gorman, a chronically unemployed ne'er do well, discovers a talent for computer programming, and is hired at the Metropolis-based conglomerate Webscoe. Gus embezzles from his employer through salami slicing, bringing him to the attention of CEO Ross Webster. Webster is intrigued by Gus's potential to help him rule the world financially. Joined by sister Vera and "psychic nutritionist" Lorelei Ambrosia, Ross blackmails Gus into helping him.

Clark Kent convinces his Daily Planet boss, Perry White, to let him return to Smallville for his high-school reunion. En route, as Superman, he extinguishes a fire in a chemical plant containing unstable Beltric acid, which produces corrosive vapor when superheated. At the reunion, Clark is reunited with childhood friend Lana Lang, a divorcée with a young son named Ricky, and harassed by Brad Wilson, her ex-boyfriend.

Infuriated by Colombia's refusal to do business with him, Ross orders Gus to command Vulcan, an American weather satellite, to create a tornado to destroy Colombia's coffee crop for the next several years. Gus travels to Smallville to use the offices of WheatKing, a subsidiary of Webscoe, to reprogram the satellite. Though Vulcan creates a devastating storm, Ross's scheme is thwarted when Superman neutralizes it, saving the harvest. Ross orders Gus to use his computer knowledge to create Kryptonite, remembering Lois Lane's Daily Planet interview with Superman. Gus uses Vulcan to locate, scan, and analyze Krypton's debris. He discovers that one of the elements of Kryptonite is an "unknown" compound, and substitutes tar.

Lana convinces Superman to appear at Ricky's birthday party, but Smallville turns it into a town celebration. Gus and Vera, disguised as Army officers, give Superman the Kryptonite, though it appears ineffective. Superman soon becomes selfish, focusing on his lust for Lana, causing him to delay rescuing a truck driver from a jackknifed rig hanging from a bridge. Superman becomes depressed, upset, and casually destructive, committing petty acts of vandalism, such as blowing out the Olympic Flame, and straightening the Leaning Tower of Pisa.

Gus, feeling used, gives Ross crude plans for a supercomputer and Ross agrees to build it in return for Gus creating an oil embargo by directing all oil tankers to the middle of the Atlantic Ocean until further notice. When the captain of one tanker insists on maintaining his original course, Ross has Lorelei seduce Superman into waylaying the tanker and breaching the hull, causing a massive oil spill. The villains decamp to the computer's location in Glen Canyon.

Superman goes on a drinking binge, is overcome by guilt, and suffers a nervous breakdown. In a junkyard, Superman splits into two personas: the immoral, corrupted Superman and the moral, righteous Clark Kent. They engage in a battle, ending when Clark strangles his evil identity. Restored to his normal self, Superman repairs the damage his counterpart caused.

After defending himself from rockets and an MX missile, Superman confronts Ross, Vera, and Lorelei. Gus's supercomputer identifies him as a threat and attempts to determine his weakness, unleashing a beam of pure Kryptonite.

Guilt-ridden and horrified by the prospect of "going down in history as the man who killed Superman", Gus destroys the Kryptonite ray with a firefighter's axe, whereupon Superman flees. The computer becomes self-aware, defending itself against Gus's attempts to disable it. Ross and Lorelei escape the control room, but Vera is transformed into a cyborg. Vera attacks her brother and Lorelei with beams of energy that immobilize them. Superman returns with a canister of the Beltric acid. Superman places the canister by the supercomputer, which does not resist as it suspects no danger. The intense heat emitted by the supercomputer causes the acid to turn volatile, destroying the supercomputer. Superman flies away with Gus, leaving Ross and his cronies to the authorities, and drops Gus off at a West Virginia coal mine, where Superman recommends him to the company as a computer programmer.

Superman returns to Metropolis. As Clark, he pays a visit to Lana, who has found employment as Perry White's new secretary. He is attacked by Brad, who has stalked Lana to Metropolis, only to end up falling into a room service cart. He restores the Leaning Tower of Pisa, and the film ends with Superman flying into the sunrise for further adventures.

Cast

 * Christopher Reeve as Clark Kent / Superman
 * Richard Pryor as August "Gus" Gorman
 * Robert Vaughn as Ross Webster
 * Annette O'Toole as Lana Lang
 * Annie Ross as Vera Webster
 * Pamela Stephenson as Lorelei Ambrosia
 * Jackie Cooper as Perry White
 * Margot Kidder as Lois Lane
 * Marc McClure as Jimmy Olsen
 * Gavan O'Herlihy as Brad Wilson