Metropolis was founded in 2213 A.D. by the United Stellar Council as the capital city of the planet XK-120, a mining planet and center of learning throughout the galaxy. That was the past. In 2315 A.D., Metropolis is invaded by the Tzorg. The new conquerer leave the planet but install a Robot Patrol System to keep the locals in check. Now the only resistance against the Tzorg occupation is a small group of resistance fighters of the Underground network. In the year 2400 A.D. the final hope to overthrow Tzorg rule over the city is to infiltrate the Tzorg Authority Complex through a recently discovered secret route, access the terminals, and shut down the robots; that is, if they had a computer specialist.
That's where the protagonist comes in. As part of yet another shipment of miners from other conquered Tzorg lands to replace the 'disappearances' of past workers, the hero has been contacted by the Underground to join their struggle against the Tzorg. The contact leaves instructions: find Spider, contact the Underground, good-bye and good luck.