The advanced race was originally supposed to be played by actors in blackface as a parable about apartheid era South Africa. This got dropped except for the city's leader Jano.
This episode was wiped by the BBC and no copy of it is known to exist.
A regular viewer of the show, Ian Stuart Black accepted this assignment because he thought that a Doctor Who credit would impress his children.
The working title for this story was The White Savages.