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.
The TARDIS is drawn into an empty white void, somewhere between universes.
When Rorvik learns that Romana is a time sensitive, he takes her prisoner, forcing her to find a way out.
As the void begins to shrink around them, Rorvik plans to take desperate measures to escape through the mirror.
With the void collapsing around them, time is running out. Rorvik ignores the Doctor's warnings.
The Keeper of Traken is nearing the end of his long reign and he requests the Doctor's help.
The Doctor and Adric are held responsible for the evil that has come to Traken.
The Keeper nears the end of his life and Melkur is poised to take control of the all powerful source manipulator.
Melkur has become the new Keeper of Traken and begins to access the source manipulator.
Deciding to repair the TARDIS's chameleon circuit, the Doctor goes to Earth to find a real police box.
The Doctor travels to the planet Logopolis in the TARDIS where a series of fateful events are set in motion.
The Master is loose on Logopolis and is determined to learn the planet's secret, but there is more at stake.
With the fate of the entire universe hanging in the balance, the Doctor and the Master are forced to collaborate.