# Doctor Who season 18

The eighteenth season of British science fiction television series Doctor Who consisted of seven four-episode serials broadcast from 30 August 1980 with the serial The Leisure Hive, to 21 March 1981 with the serial Logopolis. The season is Tom Baker's final as the Fourth Doctor before his regeneration into the Fifth Doctor (Peter Davison), as well as Lalla Ward's as companion Romana II and John Leeson's as the voice of K9. For the second time (The first being during Season 4 and third being Season 21), the entire main cast changed over the course of a single season. The season also sees the debut of Matthew Waterhouse as Adric, Sarah Sutton as Nyssa, and Janet Fielding as Tegan Jovanka, the three of whom would remain regular companions into the Fifth Doctor's era, as well as the return of the Master, portrayed both by Geoffrey Beevers and Anthony Ainley.
The season was the first to be produced by John Nathan-Turner, who would produce every season of the show until 1989, and the first to feature script editor Christopher H. Bidmead. The season features a trilogy of connected serials, Full Circle, State of Decay, and Warrior's Gate, which form a trilogy set in a "bubble universe" called E-Space, as well as The Keeper of Traken and Logopolis, the first two serials of a trilogy continued in season 19's Castrovalva, centred on the return of The Master and the regeneration of the Fourth Doctor.

## Cast
### Main cast

* Tom Baker as the Fourth Doctor
* Lalla Ward as Romana
* John Leeson as Voice of K9
* Matthew Waterhouse as Adric
* Sarah Sutton as Nyssa
* Janet Fielding as Tegan Jovanka
Season 18 is the final season of Tom Baker as the Fourth Doctor after seven years in the role. New companions Adric (Matthew Waterhouse), Nyssa (Sarah Sutton), and Tegan Jovanka (Janet Fielding) make their introductions in Full Circle, The Keeper of Traken, and Logopolis, respectively. Romana, played by Lalla Ward, departs from the series in Warriors' Gate, along with John Leeson who returns to voice the robot K9. With the arrival of Adric, this season marks the first time since 1967 that the Doctor has three regular travelling companions in the TARDIS. Peter Davison makes his first appearance as the Fifth Doctor in the closing moments of Logopolis.

### Guest stars

The Master returned to the show, this time played by Geoffrey Beevers, in The Keeper of Traken. After the events of Traken, the Master was thereafter played by Anthony Ainley, who would continue in the part for the rest of the classic series' run.
Jacqueline Hill, who had played the First Doctor's companion Barbara Wright, returned in Meglos, although playing a different character, the alien priestess Lexa.

## Serials

For Season 18 John Nathan-Turner replaces Graham Williams as producer. Barry Letts returns now as executive producer, for just this season. Christopher H. Bidmead also replaces Douglas Adams as script editor. In a return to the format of early seasons, virtually all serials from Seasons 18 through 20 are linked together, often running directly into each other. Three serials – Full Circle, State of Decay, and Warriors' Gate – are part of a trilogy within the season. These three serials include the arrival of Adric and the departure of Romana and K9.
Over the period of Christmas 1980, the season took a two-week transmission break between the broadcasts of State of Decay and Warriors' Gate.
| No. story | No. in season | Serial title | Episode titles | Directed by | Written by | Original release date | Prod. code | UK viewers (millions) | AI |
| 109 | 1 | The Leisure Hive | "Part One" | Lovett Bickford | David Fisher | 30 August 1980 (1980-8-30) | 5N | 5.9 | — |
| 109 | 1 | The Leisure Hive | "Part Two" | Lovett Bickford | David Fisher | 6 September 1980 (1980-9-6) | 5N | 5.0 | — |
| 109 | 1 | The Leisure Hive | "Part Three" | Lovett Bickford | David Fisher | 13 September 1980 (1980-9-13) | 5N | 5.0 | — |
| 109 | 1 | The Leisure Hive | "Part Four" | Lovett Bickford | David Fisher | 20 September 1980 (1980-9-20) | 5N | 4.5 | 65 |
| In search of a holiday, the Doctor and Romana travel to the famous Leisure Hive on Argolis, a planet ravaged by a nuclear war with the reptilian Foamasi years earlier. The main attraction of the Hive is a device called the Tachyon Recreation Generator, but when things start to go mysteriously wrong with the machine, the Doctor realises that evil is afoot in the Hive. He and Romana begin to unearth a tangled conspiracy which may lead to a new, deadlier war between the Argolins and the Foamasi. ||||||||||
| 110 | 2 | Meglos | "Part One" | Terence Dudley | John Flanagan & Andrew McCulloch | 27 September 1980 (1980-9-27) | 5Q | 5.0 | 61 |
| 110 | 2 | Meglos | "Part Two" | Terence Dudley | John Flanagan & Andrew McCulloch | 4 October 1980 (1980-10-4) | 5Q | 4.2 | 64 |
| 110 | 2 | Meglos | "Part Three" | Terence Dudley | John Flanagan & Andrew McCulloch | 11 October 1980 (1980-10-11) | 5Q | 4.7 | — |
| 110 | 2 | Meglos | "Part Four" | Terence Dudley | John Flanagan & Andrew McCulloch | 18 October 1980 (1980-10-18) | 5Q | 4.7 | 63 |
| The Doctor is summoned back to the planet Tigella, where the population is divided along religious and scientific lines. Something is going terribly wrong with Tigella's main power source, the Dodecahedron, but the Savants are prevented from investigating by the zealous Deons. To make matters worse, before the Doctor can solve the problem with the Dodecahedron, he is accused of its theft. The true culprit is Meglos, a shapeshifting Zolfa-Thuran, who intends to unleash the full might of the Dodecahedron upon the universe. ||||||||||
| 111 | 3 | Full Circle | "Part One" | Peter Grimwade | Andrew Smith | 25 October 1980 (1980-10-25) | 5R | 5.9 | — |
| 111 | 3 | Full Circle | "Part Two" | Peter Grimwade | Andrew Smith | 1 November 1980 (1980-11-1) | 5R | 3.7 | — |
| 111 | 3 | Full Circle | "Part Three" | Peter Grimwade | Andrew Smith | 8 November 1980 (1980-11-8) | 5R | 5.9 | — |
| 111 | 3 | Full Circle | "Part Four" | Peter Grimwade | Andrew Smith | 15 November 1980 (1980-11-15) | 5R | 5.4 | 65 |
| Romana is recalled to Gallifrey, but en route the TARDIS is drawn through a Charged Vacuum Emboitment into another universe, called E-Space. Landing on the planet Alzarius, the Doctor meets a group of humans who are trying to rebuild their spacecraft which crashlanded generations ago. When Marshmen begin rising from the swamps during the dreaded time of Mistfall, however, the Doctor realises that there is something amiss on Alzarius, and begins to unravel a genetic riddle which stretches back centuries. ||||||||||
| 112 | 4 | State of Decay | "Part One" | Peter Moffatt | Terrance Dicks | 22 November 1980 (1980-11-22) | 5P | 5.8 | — |
| 112 | 4 | State of Decay | "Part Two" | Peter Moffatt | Terrance Dicks | 29 November 1980 (1980-11-29) | 5P | 5.3 | — |
| 112 | 4 | State of Decay | "Part Three" | Peter Moffatt | Terrance Dicks | 6 December 1980 (1980-12-6) | 5P | 4.4 | — |
| 112 | 4 | State of Decay | "Part Four" | Peter Moffatt | Terrance Dicks | 13 December 1980 (1980-12-13) | 5P | 5.4 | 69 |
| Still trapped in E-Space, the TARDIS materialises on a medieval planet. The townsfolk live in fear of the Three Who Rule, who govern from their mighty castle. Investigating, the Doctor discovers that the Three Who Rule are ancient astronauts who were turned into vampires long ago, and their castle is actually their spaceship. When Romana and Adric are kidnapped, the Doctor must ally himself with a band of renegade peasants to stop the resurrection of one of Gallifrey's greatest enemies: the Great Vampire itself. ||||||||||
| 113 | 5 | Warriors' Gate | "Part One" | Paul Joyce & Graeme Harper (uncredited) | Stephen Gallagher | 3 January 1981 (1981-1-3) | 5S | 7.1 | 59 |
| 113 | 5 | Warriors' Gate | "Part Two" | Paul Joyce & Graeme Harper (uncredited) | Stephen Gallagher | 10 January 1981 (1981-1-10) | 5S | 6.7 | — |
| 113 | 5 | Warriors' Gate | "Part Three" | Paul Joyce & Graeme Harper (uncredited) | Stephen Gallagher | 17 January 1981 (1981-1-17) | 5S | 8.3 | — |
| 113 | 5 | Warriors' Gate | "Part Four" | Paul Joyce & Graeme Harper (uncredited) | Stephen Gallagher | 24 January 1981 (1981-1-24) | 5S | 7.8 | 59 |
| Trying to escape from E-Space, the Doctor, Romana, Adric and K9 instead land in an eerie white void whose only feature is a crumbling old keep. Also trapped in the void is a slave ship captained by the cruel Rorvik, whose time sensitive pilot, the leonine Tharil Biroc, escapes and lures the Doctor into the keep and the mirror gateway beyond. There, the Doctor witnesses the rise and fall of the once-mighty Tharil Empire. He realises that he must free the Tharils enslaved on the ship and escape through the gateway, before Rorvik's vengeful actions destroy them all. ||||||||||
| 114 | 6 | The Keeper of Traken | "Part One" | John Black | Johnny Byrne | 31 January 1981 (1981-1-31) | 5T | 7.6 | — |
| 114 | 6 | The Keeper of Traken | "Part Two" | John Black | Johnny Byrne | 7 February 1981 (1981-2-7) | 5T | 6.1 | — |
| 114 | 6 | The Keeper of Traken | "Part Three" | John Black | Johnny Byrne | 14 February 1981 (1981-2-14) | 5T | 5.2 | — |
| 114 | 6 | The Keeper of Traken | "Part Four" | John Black | Johnny Byrne | 21 February 1981 (1981-2-21) | 5T | 6.1 | 63 |
| The Union of Traken is governed by a Keeper gifted with the powers of the Source. The current Keeper is nearing the end of his thousand-year tenure, however, and asks the Doctor and Adric – who have escaped from E-Space – to go to Traken and stop an evil he believes is plotting to destroy the Union. But the source of the evil, the Melkur, has already infiltrated the Consuls of Traken, and has the Doctor declared a criminal. Allying himself with Consul Tremas and his daughter, Nyssa, the Time Lord must uncover the true power behind the Melkur – someone who knows the Doctor of old. ||||||||||
| 115 | 7 | Logopolis | "Part One" | Peter Grimwade | Christopher H. Bidmead | 28 February 1981 (1981-2-28) | 5V | 7.7 | — |
| 115 | 7 | Logopolis | "Part Two" | Peter Grimwade | Christopher H. Bidmead | 7 March 1981 (1981-3-7) | 5V | 7.7 | 61 |
| 115 | 7 | Logopolis | "Part Three" | Peter Grimwade | Christopher H. Bidmead | 14 March 1981 (1981-3-14) | 5V | 5.8 | — |
| 115 | 7 | Logopolis | "Part Four" | Peter Grimwade | Christopher H. Bidmead | 21 March 1981 (1981-3-21) | 5V | 6.1 | 65 |
| After her aunt is murdered by the Master, an airline stewardess named Tegan Jovanka becomes an unwitting stowaway aboard the TARDIS as it travels to the planet Logopolis. There, the Doctor discovers that the Master's interference with the Logopolitans' advanced mathematics has unleashed a wave of entropy which threatens to consume the entire universe. The two Time Lords enter into an uneasy alliance. Their only hope lies on Earth... but then, in the moment of greatest crisis, the Master plays his ultimate trump card. ||||||||||

## Broadcast

The entire season was broadcast from 30 August 1980 to 21 March 1981.

## Home media
### VHS releases

| Season | Story no. | Serial name | Number and duration of episodes | UK release date | Australia release date | USA/Canada release date |
| 18 | 109 | The Leisure Hive | 4 x 25 min. | January 1997 | September 1997 | May 1997 |
| 18 | 110 | Meglos | 4 x 25 min | March 2003 | June 2003 | October 2003 |
| 18 | 111 112 113 | The E-Space Trilogy Full Circle State of Decay Warriors' Gate | 12 x 25 min | November 1997 3 x VHS | October 1997 3 x VHS | July 1998 3 x VHS |
| 18 | 114 | The Keeper of Traken | 4 x 25 min | June 1993 | September 1993 | February 1994 |
| 18 | 115 | Logopolis | 4 x 25 min | March 1992 | September 1992 | October 1993 |

### DVD and Blu-ray releases

All releases are for DVD unless otherwise indicated:
* $^{(B)}$ indicates a Blu-ray release
| Season | Story no. | Serial name | Number and duration of episodes | R2 release date | R4 release date | R1 release date |
| 18 | 109 | The Leisure Hive | 4 × 25 min. | 5 July 2004 | 7 October 2004 | 7 June 2005 |
| 18 | 110 | Meglos | 4 × 25 min. | 10 January 2011 | 20 January 2011 | 11 January 2011 |
| 18 | 111–113 | Full Circle State of Decay Warriors' Gate | 12 × 25 min. | 26 January 2009 | 9 April 2009 | 5 May 2009 |
| 18 | 114 | The Keeper of Traken | 4 × 25 min. | 29 January 2007 | 7 March 2007 | 5 June 2007 |
| 18 | 115 | Logopolis | 4 × 25 min. | 29 January 2007 | 7 March 2007 | 5 June 2007 |
| 18 | 109–115 | Complete Season 18 | 28 × 25 min. 1 × 50 min. | 18 March 2019 $^{(B)}$ | 17 April 2019 $^{(B)}$ | 19 March 2019 $^{(B)}$ |
* ↑ Known collectively as The E-Space Trilogy. Each serial comprises four episodes.
* ↑ Only available as part of the New Beginnings box set in Regions 2 and 4. Available individually or in the box set in Region 1.
* ↑ Available as part of the New Beginnings box set or the Regeneration box set in Region 2. Only available as part of the New Beginnings box set in Region 4. Available individually or as part of the New Beginnings box set in Region 1.
* ↑ Released as Doctor Who: The Collection – Season 18 in Region B. Released as Doctor Who – Tom Baker: Complete Season Seven in Region A.

## In print

| Season | Story no. | Library no. | Novelisation title | Author | Hardcover release date | Paperback release date | Audiobook release date |
| 18 | 109 | 39 | Doctor Who and the Leisure Hive | David Fisher | 22 July 1982 | 22 July 1982 | 1 July 2013 |
| 18 | 110 | 75 | Meglos | Terrance Dicks | 17 February 1983 | 19 May 1983 | 1 July 2021 |
| 18 | 111 | 26 | Full Circle | Andrew Smith | 16 September 1982 | 16 September 1982 | 15 January 2015 |
| 18 | 112 | — | State of Decay | Terrance Dicks | — | — | June 1981 |
| 18 | 112 | 58 | Doctor Who and the State of Decay | Terrance Dicks | 17 September 1981 | 14 January 1982 | 7 January 2016 |
| 18 | 113 | 71 | Doctor Who and Warriors' Gate | Stephen Gallagher (as John Lydecker) | 15 April 1982 | 15 April 1982 | — |
| 18 | 113 | — | Warriors' Gate | Stephen Gallagher (as John Lydecker) | — | 13 July 2023 | 4 April 2019 |
| 18 | 114 | 37 | Doctor Who and the Keeper of Traken | Terrance Dicks | 20 May 1982 | 20 May 1982 | 1 October 2020 |
| 18 | 115 | 41 | Logopolis | Christopher H. Bidmead | 21 October 1982 | 21 October 1982 | 4 February 2010 |
* ↑ Number in Target's Doctor Who Library, if applicable
* ↑ Published by Target's parent companies (Allen Wingate, W. H. Allen, BBC Books) unless otherwise indicated
* ↑ Published by Target Books (or by BBC Books under the Target Collection umbrella) unless otherwise indicated
* ↑ Unabridged from BBC Audio/AudioGo unless otherwise indicated
* ↑ Original novelisation exclusive to audio
* ↑ Published by Pickwick Talking Books
* ↑ Print version of the expanded edition is credited solely to Gallagher
* ↑ Expanded and restored original version as submitted to Target before John Nathan-Turner demanded that it match the transmitted version more closely. Print version is titled Warriors' Gate and Beyond as it includes two short stories.