: The story is loosely based on the Greek legend of Jason and the Argonauts , specifically their quest for the Golden Fleece, with "Underworld" serving as a sci-fi retelling of the journey to Colchis. Critical Reception & Production
The code refers to Part Two of the 1978 Doctor Who serial titled " Underworld ". This episode is the 18th in the show's 15th season and features the Fourth Doctor, played by Tom Baker. Plot Overview
: The society is controlled by "The Seers," who value radioactive energy over human life.