The Horns Of Nimon - The inhabitants of the planet Skonnos have been promised by an alien Nimon that he will restore their empire to greatness if they in return provide young sacrifices and radioactive hymetusite crystals, both of which they are obtaining from the nearby planet Aneth. With the TARDIS immobilised for repairs, the Doctor and Romana encounter the Skonnan spaceship transporting the latest sacrificial consignment from Aneth.

The Time Monster - The Master, in the guise of Professor Thascales, has constructed at the Newton Institute in Wootton a device known as TOMTIT - Transmission Of Matter Through Interstitial Time - with which to gain control over Kronos, a creature from outside time.

Underworld - The TARDIS arrives on a Minyan space craft, the R1C, commanded by a man named Jackson. Jackson and his crew are on a long quest to recover the Minyan race banks from a ship called the P7E which left their planet centuries ago. The Doctor helps to free the R1C after it becomes buried in a meteorite storm, but it then crashes into another newly-formed planet.