The TARDIS makes an emergency landing on Varos, a planet that used to be a penal colony, and where the native Varosians are presently entertained by broadcasts of real violence and death. Mistaken for rebels, the Doctor and Peri learn that Sil, an evil delegate of the Galatron mining corporation, bids to rule Varos and to control supplies of Zeiton 7 ore, which is the...