The Invasion of Time

The Doctor is behaving oddly, having clandestine meetings with a race known as the Vardans who can travel via the power of thought. Leela is concerned - and she worries further when she learns that K9 has been instructed to shoot her if she attempts to interfere.

Returning home to Gallifrey, the Doctor demands to take over as Lord President of the High Council of Time Lords. With no one able to dispute his claim, he is inducted and begins a systematic purge of Time Lord society, expelling many high ranking officials - and Leela - to the wastes of Outer Gallifrey.

It seems that the Doctor has joined forces with the Vardans, and is helping in their attempted conquest of Gallifrey out of revenge for his treatment at the hands of previous High Councils. The Vardans want the secrets of time travel and with only his old teacher, Cardinal Borusa, at his side, the Doctor appears to be granting them their wish. But not everything is exactly what it seems. The Doctor has an agenda hidden from the Vardans - and they in turn have a far darker one hidden from him.

• "The Invasion of Time" is the final story for the popular companion, the warrior Leela.

• Season 15 went out with a whimper rather than a bang.  Leela was abruptly written out of the show, suffering the fate of many a companion by marriage.  Although Louise Jameson (Leela) had given producer Graham Williams more than ample warning of her intention to leave at the end of her contract, Williams put off writing her departure in hopes that she would be persuaded to stay on for another season.  The rushed departure scene greatly disappointed Jameson, who felt Leela should go out with a bang (such as sacrificing her life to save others).

• Most annoying of all is the ever popular "I can't remember a thing that's happened to me over the last 6 episodes" line which the Doctor proclaims with 3 minutes remaining in episode 6.  

• The production values were also low, using noisy on-site locations for the interior of the TARDIS.   This was in response to high "immanent industrial action" or in other words - a strike.  By moving to film on location, they were able to complete this story.  Similar union tensions were to take their toll two years later on the season 17 finale, "Shada."

• The story does have its moments, such as the Doctor seemingly turning Gallifrey over to an alien invasion and the surprising appearance of the Sontarans at the end of episode 4.  

• K-9 was written out at the end of this story, or at least partially.  It was hoped that over the break in seasons that a newer model could be developed that would be more reliable.  Thus was K-9 Mark II born.

• The character of Borusa (last seen in "The Deadly Assassin") was played this time by actor John Arnatt.  Borusa was originally played by Angus MacKay, however he was unable to return to reprise his role. 

• Milton Johns makes his final appearance in Doctor Who as the slimey Castellan Kelner.  His first appearance in Doctor Who was as the sadistic Benik in the Patrick Troughton story "The Enemy of the World."   He later returned in the Tom Baker story "The Android Invasion."