The Doctor and Romana receive a distress signal and arrive on Chloris, a lush and verdant world that has only small quantities of metals, all of which are controlled by its ruler, Lady Adrasta. Adrasta keeps order with the aid of her Huntsman and his wolfweeds - mobile balls of vegetation while a band of scruffy thieves, led by Torvin, organize raids on her palace to steal whatever metal they can.
The Doctor identifies the distress signal's source as a large eggshell-like structure in the forest. He is taken prisoner By Adrasta's guards and, in order to escape, leaps into the Pit - the entrance to a cave system into which all who incur Adrasta's wrath are consigned to be devoured by an immense green globular creature living within. Can the Doctor escape from the creature of the Pit and save Chloris? Originally transmitted in 1979.