It was administered by Gatherer Hade, who taxed the citizens. He in turn served the Collector, the company's senior representative on the planet. The Collector had his palace in Megropolis One. The Company's Correction Centre was built beneath. Under Megropolis One was the undercity, where the outlaws gathered. Orders were given to the populace via the public video system, the output of which was controlled from the palace. The population could also be observed through oculoid electronic monitors.
The Fourth Doctor and Leela visited Megropolis One and befriended Cordo. Together, they escaped from the Company into the undercity. Mandrel, the leader of the outlaws, had the Doctor return into the city with a consumcard. He took this to the Consum Bank, but, as it was stolen, balerium gas was released, knocking him unconscious. Workers came and took him away to the Correction Centre.
Hearing of this from Cordo, Leela entered the city and, with the assistance of K9, broke into the centre. The Doctor had been released already by Hade, who hoped he would lead him to others involved in what Hade believed was a plot to overthrow the Company.
Upon returning to the undercity, the Doctor, with the help of Bisham, spurred the outlaws into rebellion. They began encouraging dissent among the workers. Meanwhile, the Doctor, Mandrel, Bisham and Cordo entered the city. They went to Main Control and closed down the vapour towers, preventing the release of PCM, a drug used to control the population.
Leela was to be executed in Megropolis One by steaming. This, and a bounty for information of the Doctor, were broadcast on the public video system. The Doctor rescued Leela and they broke into the palace. There they managed to take control of the video system and broadcast messages to the entire city, supporting the rebellion. This, coupled with the rebels spurring the workers on, led to mass defiance of the Company.
Gatherer Hade attempted to quell those on the rooftops, a restricted zone, but was picked up and thrown to his death. The Collector, stressed by the alterations the Doctor had made to his taxation, reverted to his natural Usurian form — seaweed-like in appearance. Megropolis One was freed and, before leaving, the Doctor urged the population to find a way to return to Earth. (TV: The Sun Makers)