This season introduced K9 to the series and saw the departure of Leela. It was originally intended to include Terrance Dicks' story The Vampire Mutations but, due to a major BBC production of Dracula, it was postponed. It later became Season 18's State of Decay. To replace it, Dicks quickly scripted the season opener, Horror of Fang Rock. The season took a two week transmission break over the 1977 Christmas period, between the broadcast of part four of The Sun Makers and part one of Underworld.
Episodes
E1
1. Horror of Fang Rock (1)
7.3
September 3, 1977
25 min
The English channel, the 1900s AD. The TARDIS lands on barren Fang Rock, inhabited until now only by three lighthouse keepers. But what is the strange fog covering the island, and can it be connected to the falling star sighted earlier that night?
The survivors of a wrecked ship are stranded with the lighhouse crew on Fang Rock as a deadly menace slithers through the fog. Has the Beast of Fang Rock returned?
Guest Stars:
Colin Douglas, John Abbott, Sean Caffrey, Alan Rowe, Rio Fanning
E3
3. Horror of Fang Rock (3)
7.0
September 17, 1977
25 min
The Doctor barricades everyone in the lighthouse to protect them from the mysterious deadly creature in the fog. But it may already be inside, biding its time…
Guest Stars:
Colin Douglas, John Abbott, Sean Caffrey, Alan Rowe, Rio Fanning
E4
4. Horror of Fang Rock (4)
7.0
September 24, 1977
25 min
The Rutan starts picking off the surviving humans one by one as the Doctor and Leela struggle to defeat not only the alien but an entire fleet waiting to occupy Earth.
Guest Stars:
Colin Douglas, John Abbott, Sean Caffrey, Alan Rowe, Annette Woollett
E5
5. The Invisible Enemy (1)
6.5
October 1, 1977
25 min
Deep space, 5000AD. An Earth supply shuttle is infected by a strange sentient space-borne virus, which quickly spreads to the crew of the refuelling station on the moon Titan. Even worse, the Doctor himself falls victim. But why is Leela immune, and what is the virus's ultimate goal?
Guest Stars:
Michael Sheard, Brian Grellis, Edmund Pegge, Jay Neill, Anthony Rowlands
E6
6. The Invisible Enemy (2)
6.7
October 8, 1977
25 min
Leela and Lowe take the Doctor to the Bi-Al Foundation for help. But how can they cure an infection of the mind?
Guest Stars:
Michael Sheard, Brian Grellis, Frederick Jaeger, Roy Herrick, Elizabeth Norman
E7
7. The Invisible Enemy (3)
7.0
October 15, 1977
25 min
Miniaturised clones of the Doctor and Leela are injected into his brain. But they must now fight the virus on its own level. And its servants are closing in around them.
Guest Stars:
Michael Sheard, Frederick Jaeger, Roy Herrick, Elizabeth Norman, Jim McManus
E8
8. The Invisible Enemy (4)
6.8
October 22, 1977
25 min
The Nucleus, now grown to human size, is determined to spawn and take over the Galaxy. Only the Doctor and Leela can stop it.
Guest Stars:
Michael Sheard, Brian Grellis, Frederick Jaeger, Jim McManus, Pat Gorman
E9
9. Image of the Fendahl (1)
6.0
October 29, 1977
25 min
England, the late 1970s. At Fetch Priory, Dr Fendelman's experiments with the new Time Scanner are disrupted by the mysterious death of a hiker, nearby. Then there's the mysterious skull, also being used as part of his work. A skull that seems to predate the evolution of mankind. What is the true role of the Fendahl in humanity's evolution?
Guest Stars:
Wanda Ventham, Daphne Heard, Denis Lill, Edward Evans, Scott Fredericks
E10
10. Image of the Fendahl (2)
5.8
November 5, 1977
25 min
The mystery surrounding the strange skull deepens. Thea is slowly succumbing to its influence while the Doctor prepares to battle a creature from mythology.
Guest Stars:
Wanda Ventham, Daphne Heard, Denis Lill, Edward Evans, Scott Fredericks
E11
11. Image of the Fendahl (3)
6.2
November 12, 1977
25 min
While Max prepares to tap supernatural forces beyond imagining, the Doctor and Leela investigate the legend of the Fendahl.
Guest Stars:
Wanda Ventham, Daphne Heard, Denis Lill, Edward Evans, Scott Fredericks
E12
12. Image of the Fendahl (4)
6.2
November 19, 1977
25 min
The Fendahl is returning to life, ready to consume everything in its path. Can the Doctor find a way to kill death itself?
Guest Stars:
Wanda Ventham, Daphne Heard, Edward Evans, Scott Fredericks, Edward Arthur
E13
13. The Sun Makers (1)
6.6
November 26, 1977
25 min
Pluto, the distant future. The planet has been terraformed and is now orbited by artificial suns, provided by the rapacious company who ruthlessly exploit the relocated human workforce. The Doctor, Leela, and K9 arrive and befriend a luckless drone worker, but they must flee with him to the dark undercity...
Guest Stars:
Richard Leech, Jonina Scott, Roy Macready, William Simons, Michael Keating
E14
14. The Sun Makers (2)
6.5
December 3, 1977
25 min
The Doctor has been captured by the Gatherer. Leela works to free him but the Gatherer is already laying his own plans…
Guest Stars:
Richard Leech, Jonina Scott, Roy Macready, William Simons, Michael Keating
E15
15. The Sun Makers (3)
6.8
December 10, 1977
25 min
Now Leela is the prisoner of the Collector. He knows of the Doctor and is determined to rid himself of both of them.
Guest Stars:
Richard Leech, Jonina Scott, Roy Macready, William Simons, Michael Keating
E16
16. The Sun Makers (4)
6.2
December 17, 1977
25 min
The Doctor now moves to completely overthrow the Company. But the Collector has one last trump card to play.
Guest Stars:
Tom Kelly, Richard Leech, Jonina Scott, Roy Macready, William Simons
E17
17. Underworld (1)
5.8
January 7, 1978
25 min
Deep space, an unknown time. The Doctor encounters the Minyans, survivors of a race the Time Lords unwittingly obliterated early in their own history. The Minyans are searching for their race's lost gene banks, a quest which takes them to the edge of the galaxy…
Guest Stars:
James Maxwell, Alan Lake, Jonathan Newth, Imogen Bickford-Smith
E18
18. Underworld (2)
6.0
January 14, 1978
25 min
After 100,000 years, the Minyans have found the long-lost P7E. But what awaits them on the ship, long buried in the core of a newborn planet?
Guest Stars:
James Maxwell, Alan Lake, Jonathan Newth, James Marcus, Imogen Bickford-Smith
E19
19. Underworld (3)
6.0
January 21, 1978
25 min
The Minyans have, at long last, found the P7E. But a host of guards and robotic seers stand between them and the race banks.
Guest Stars:
James Maxwell, Alan Lake, Jonathan Newth, James Marcus, Imogen Bickford-Smith
E20
20. Underworld (4)
6.2
January 28, 1978
25 min
The Minyons struggle to gain the precious race banks from the Oracle. But perhaps it is giving in a little too easily ...
Guest Stars:
James Maxwell, Alan Lake, Jonathan Newth, James Marcus, Imogen Bickford-Smith
E21
21. The Invasion of Time (1)
7.2
February 4, 1978
25 min
Gallifrey, world of the Time Lords. The Doctor returns and claims the vacant presidency. But his behaviour is erratic and his motives mysterious.
Guest Stars:
Stan McGowan, Tom Kelly, Chris Tranchell, Milton Johns, John Arnatt
E22
22. The Invasion of Time (2)
7.2
February 11, 1978
25 min
The Doctor is made president of the Time Lords. He immediately orders K-9 to lower the planet's defences and has Leela banished to the wilderness.
Guest Stars:
Stan McGowan, Chris Tranchell, Milton Johns, John Arnatt, Charles Morgan
E23
23. The Invasion of Time (3)
6.6
February 18, 1978
25 min
The Doctor has betrayed his own people and enabled a Vardan invasion of Gallifrey. Leela joins forces with the Outsiders and prepares to strike back against the aliens.
Guest Stars:
Stan McGowan, Chris Tranchell, Milton Johns, John Arnatt, Charles Morgan
E24
24. The Invasion of Time (4)
6.6
February 25, 1978
25 min
The Doctor works to free his planet of the Vardan menace. How can he defeat an enemy who can read his very thoughts? And does their invasion conceal a greater menace?
Guest Stars:
Chris Tranchell, Milton Johns, Ray Callaghan, Hilary Ryan, Michael Mundell
E25
25. The Invasion of Time (5)
7.2
March 4, 1978
25 min
The Sontarans have invaded Gallifrey, seeking to seize the incredible power of the Time Lords. The Doctor's first step is to cut them off from their fleet. But Kelner is helping the enemy…
Guest Stars:
Chris Tranchell, Milton Johns, John Arnatt, Ray Callaghan, Hilary Ryan
E26
26. The Invasion of Time (6)
7.0
March 11, 1978
25 min
The Sontarans finally invade the TARDIS itself, seeking the Great Key. The Doctor, however, has other uses for this powerful object…
Guest Stars:
Chris Tranchell, Milton Johns, John Arnatt, Hilary Ryan, Max Faulkner