A talented computer hacker, August "Gus" Gorman is unemployed and down on his luck. Finally landing a job at Webscoe Industries by happenstance, he balks at the figure of his first paycheck, which is $143.80½. But, once he'd learned that all of the other ½ cents are left floating around inside the megacorporation's database, Gorman hacked into the company's computer system and funneled them all into his next check, accruing the amount of $85,789.90 (this form of hacking is known as salami slicing).
Having gained the attention of Webscoe's owner Ross Webster (by driving a red sportscar to work one morning), Gorman is given the choice of either going to jail or helping Webster gain economic control over the world, starting with the coffee industry. Accepting Webster's ultimatum, Gorman creates a massive storm to wipe out Colombia's coffee crops (Webster's primary target) with the use of a weather satellite. After Superman disperses the storm before any real damage can be done, Gorman is charged with synthesizing Kryptonite to destroy Superman. Chemical analysis allows Gorman to determine the various properties of Kryptonite except a small portion that is "unknown". He decides to substitute tar (inspired by a pack of cigarettes he is smoking) and develops an offshoot of Kryptonite that creates an Bizarro who terrorizes the world. This provides Webster an advantage, as he has more plans for Gorman.
Suddenly sick of Webster's megalomaniacal attitude, Gorman demands that Webster give him the means to build a particular supercomputer of his own design. Frustrated by Gorman as well, Webster agrees to build the hacker's computer as long as he deactivates all of the oil pumps in North America and reroutes the oil tankers to the middle of the Atlantic. Reluctantly, Gorman plays his part in the new scheme.
Once the tankers had been diverted and the supercomputer completed, Gorman had a change of heart. By the time Superman made his way to Webster's hideout in the Grand Canyon, a tense battle ensued between him and Gorman's new Ultimate Computer. Gorman decides to help destroy his creation, giving Superman a chance to employ the use of a corrosive acid to the computer's foundation, causing an explosion. Afterwards, Superman carries Gorman safely away from the hideout and delivers him to a coal mine, offering the personnel a new employee. However, Gorman politely refuses, and walks off in the direction of a bus stop.
In the original version of Superman III, Gus Gorman was to be a disguise for the supervillain Brainiac in which he could live among humans. Under his Gus persona, Brainiac would then set about his evil deeds using the supercomputer which appears at the end of the film. The filmakers rejected this idea, instead using the Gus Gorman character for comic relief.