18 episodes were originally broadcast in 1980
The Doctor and Romana begin to suspect that the Nimon is only the first of a full scale invasion.
On the dying world of Crinoth, Romana discovers the truth behind the Nimon's empty promises.
The planet Argolis, the Argolins live in a huge shielded city, protected from the irradiated wasteland outside.
Romana tries to get Argolis' tachyon machine working properly, but the consequences could be dramatic.
The Doctor, aged by the unstable tachyon machine, finally uncovers the truth about the tachyon generator.
Pangol begins his plan for a rebirth of Argolis — a rebirth that will start by resuming their ancient war.
Meglos plans to steal the ancient and powerful Dodecahedron from the neighbouring world of Tigella.
Masquerading as the Doctor, Meglos penetrates the underground city of Tigella.
While Meglos escapes with the Dodecahedron, the Doctor is mistakenly held responsible for the theft.
The Doctor must convince the Tigellans of his innocence if he is to prevent Meglos from using the dodecahedron.
The TARDIS enters the universe of E-Space and lands on the planet Alzarius where Mistfall is occurring.
The Doctor and K-9 are stranded when the TARDIS is stolen by the Marshmen.
The Doctor and Romana are taken to the tower and meet the three mysterious rulers.
Marshmen are on the rampage through the ship and the Doctor finally uncovers the tragic truth of the Starliner.
The TARDIS lands on a world in E-Space where the primitive inhabitants of a village live in fear.
The Doctor and Romana are taken to the tower and meet the three mysterious rulers.
As the Great Vampire begins to awaken from his long sleep, the Doctor formulates a desperate plan.