Rima was a Peladonian miner who was trapped in the power struggle between Ettis and Gebek in the trisilicate mines of the planet Peladon. Though willing to listen to Ettis' ideas of class revolt, he was taken aback by Ettis' outright dismissal of Gebek's more level-headed approach. When Gebek and the Third Doctor appeared to be in trouble, an informal "council of miners" gathered to plan a course of action. Ettis tried to convince the others that the duo be abandoned to their fate, but Rima successfully moved that the miners instead send out a search and rescue party.
Despite this clash of wills, Ettis continued to confide in Rima. On one occasion, Ettis told him of his plans to use the sonic lance to destroy the whole of the royal court, and several mining levels, as well. It was at this juncture that Rima finally saw Ettis as mentally unstable. When he threatened to tell other miners that Ettis' judgment had become impaired, Ettis stabbed him. Sarah Jane Smith nursed his wounds, but he died. (TV: The Monster of Peladon)