Hezrah was a city on a planet visited by the Third Doctor and Sarah Jane Smith. The people there worshiped "the Eternal Machine", which would send chosen citizens to the stars. The Doctor revealed that the machine was actually an alien that would slowly touch and kill the citizens, in order to gain power. Once it was powerful enough, it would have left the planet and its followers. The creature's followers grew angry at the creature and set it ablaze, killing it. (PROSE: The Discourse of Flies)