Gus Gorman (Richard Pryor) takes a programming course in Superman III and soon becomes a computer expert. After his employer, Ross Webster (Robert Vaughn), catches him embezzling funds through the company's computer system, he hires the wiz for his own scam. Webster wants Gus to plug into the Vulcan weather satellite and instruct it to change the climate of Columbia, thus destroying the South American coffee crop so he can corner the market. Obsessed with controlling the distribution of the world's resources, the nefarious schemer next agrees to build Gorman a supercomputer.
Superman (Christopher Reeves), meanwhile, continues to perform miraculous deeds, such as putting out a chemical fire by turning a lake into ice and dropping it over the conflagration. Then Supe even falls in love with Lana Lang (Annette O'Toole), an old flame he meets at a high school reunion. After being exposed to a bad batch of Kryptonite, he undergoes an identity crisis which is only resolved when the two halves of his personality Clark Kent and the Man of Steel have a full-out brawl. Then Gus's new computer turns into a death machine with a mind of its own (similar to Hal in Stanely Kubrick's 2001: A Space Odyssey), and Superman must use all his powers to destroy it. Although the film goes on far too long, our hero wins out over the machine in a dazzling finale.
Screenplay writer David Newman has noted: "I think now everyone harbors a secret fear of computers. Nobody seems to understand them. They seem to be in control. Indeed, machine consciousness may be achieved once the programmers figure out how to tell a computer to think about thinking and to understand its own process of understanding. American and Japanese scientists are working on this challenge, which some view as being more adventuresome than putting astronauts in space."
Director Richard Lester uses the same slapstick finesse he demonstrated in The Three Musketeers to point out how wobbly the human ego often is during crisis situations. The film reminds us that even if silicon sensibilities never love, grieve or fear, intelligent computers have already changed our sense of self as the only reasoning beings. Humanity has survived other jolts to its ego, from Copernicus to Darwin, and it will have to cope with this one too.