Season 15 episodes

No   Code   Title                    First Shown  Eps  Exists
-------------------------------------------------------------
92    4V    Horror of Fang Rock        3 Sep 77    4    all
93    4T    The Invisible Enemy        1 Oct 77    4    all
94    4X    Image of the Fendahl      29 Oct 77    4    all
95    4W    The Sun Makers            26 Nov 77    4    all
96    4Y    Underworld                24 Dec 77    4    all
97    4Z    The Invasion of Time      21 Jan 78    6    all

Notes:

K9 joins as a companion in The Invisible Enemy. Leela leaves to stay on Gallifrey at the end of The Invasion of Time.

Episode Details

Horror of Fang Rock

The Doctor promises to take Leela to Brighton for a holiday. Instead, the TARDIS materialises on Fang Rock, inhabited only by the keepers of the Lighthouse. The light behaves erratically, causing a clipper to run aground. The lighthouse engineer dies in mysterious circumstances, and the remaining keepers and the clipper survivors start to die one by one. Can the Doctor and Leela uncover the mystery before everyone is dead?

The Invisible Enemy

A sentient space virus attacks the crew of a shuttlecraft on its way to a base of Titan. The virus also enters the TARDIS circuits and infects the Doctor, who starts behaving strangely, landing the TARDIS on Titan. The shuttle crew and the Doctor then attempt to kill Leela. Can she survive and help the Doctor fight the virus that's controlling him?

Image of the Fendahl

A 12 million year old skull starts to exhibit strange powers. The Doctor realises that the feared Fendahl, a race known only from a Time Lord fairy story, is back - and the Earth is in deadly danger!

The Sun Makers

Arriving at a human colony living in an artificial biosphere on Pluto, the doctor discovers a citizen on the verge of committing suicide because of an impossible tax burden. Aiding the resistance, the Doctor discovers that the corrupt corporation controlling the colony is being run by an evil alien...

Underworld

The TARDIS lands on a space craft on a many century mission, and the Doctor is immediately recognised as a Time Lord, much to his surprise. He aids the Minyans to locate their goal, a vessel known as P7E which is now at the centre of an asteroid. As the Minyans attempt to recover the gene bank that contains their race, they clash with the half-robot/half-Minyan rulers of the asteroid.

The Invasion of Time

Gallifrey is under attack by a mysterious force, and it seems that the Doctor is a traitor. Can he uncover the real villains before they completely destroy the planet Gallifrey...