|22 episodes comprising 6 stories|
|starting with Arc of Infinity|
|Companion(s):||Tegan, Turlough, Nyssa|
|Script editor(s):||Eric Saward|
|Start date:||3 January 1983|
|End date:||16 March 1983|
|Typical episode length:||25'|
|Key reference books about the season:||The Discontinuity Guide, The Fifth Doctor Handbook, The Eighties, JN-T: The Life and Scandalous Times, About Time 5|
|Key documentaries about the season:||Being Doctor Who, Mouth on Legs, Casting Off!|
|Relevant Myth Makers interviews:||Janet Fielding, Sarah Sutton, Peter Grimwade, John Nathan-Turner, Mark Strikcson, Eric Saward|
Season 20 of Doctor Who was Peter Davison's second season as the Fifth Doctor, and it ran between 3 January 1983 and 16 March 1983. Before the season ended, Nyssa had departed, Turlough had arrived, and the Brigadier had returned. Every story of this season contained an old enemy of the Doctor in at least a minor role, to celebrate the twentieth anniversary of the show.
Structurally, the season retread season 18's formula of including a trilogy of stories bound together by an overarching theme. In this instance, the tripartite tale involved Turlough's attempts to kill the Doctor at the behest of the Black Guardian.
Season 20 was notable for the degree to which it varied from its original plans. It had been commissioned as a 28-part series, and the intent was that it would have actually been broadcast towards the end of 1982. Producer John Nathan-Turner had hoped to use season 20 as a way to reverse the January-March broadast of season 19. Thus, he had initially obtained permission to record and broadcast season 20 in 1982, thus making season 21 broadcast over the milestone 23 November 1983. Had JNT got his way, the twentieth anniversary special would have in fact been a part of the regular twenty-first season.
Although this idea was in fact greenlit, permission had to be rescinded when it was discovered that Davison's second job — the then-popular BBC One comedy, Sink or Swim — wouldn't allow for this more aggressive Doctor Who production schedule. BBC One controller, Alan Hart, had to personally step in to settle the dispute between the two production teams, and he "awarded" Davison to Sink or Swim. This meant that season 20 would, like its predecessor, be broadcast in the first quarter of 1983.
Hart, however, did want some sort of anniversary special in November, so he suggested that JNT put the money for two of the 28 episodes aside to allow for the special. This of course meant that there would now be 26 episodes in season 20. In the end, however, the final four episodes — meant to go towards a Dalek adventure that eventually became season 21's Resurrection of the Daleks — were left on the table because of a union dispute. Thus, as transmitted, season 20 consisted of just 22 episodes.
Meanwhile, the anniversary special, which was originally envisaged as a part of season 21, was something quite separate from any season. Although it used a portion of the original money involved in the season 20 commission, it received a separate commission from Head of Series David Reid on 15 July 1982, long after season 20 had wrapped. Indeed, it only received this commission because JNT had been able to secure co-production money from the main Australian network. Moreover, The Five Doctors, as the production was eventually called, didn't begin principal photography until early March 1983 — just when season 20 was wrapping transmission on television.
The Five Doctors, though often said to be a part of season 20, was therefore not a part of season 20 in any production or broadcast sense. Indeed, it's doubtful that any contemporary viewer thought of it as a part of the season, since it came almost eight months after the closing scene of The King's Demons. Instead, it had much greater production and broadcast proximity to season 21.
|1||Arc of Infinity||Johnny Byrne||4||First and final onscreen appearance of Omega since 1973.|
|2||Snakedance||Christopher Bailey||4||Return and final onscreen appearance of the Mara.|
|3||Mawdryn Undead||Peter Grimwade||4||First appearance of Vislor Turlough; reintroduction of Brigadier Lethbridge-Stewart. First story in the "Black Guardian Trilogy". Narrative concerning the year of the story's setting fueled the UNIT dating controversy.|
|4||Terminus||Steve Gallagher||4||Final appearance of Nyssa. Second story in the "Black Guardian Trilogy".|
|5||Enlightenment||Barbara Clegg||4||Final appearances of the Black Guardian and the White Guardian. Third and final story in the "Black Guardian Trilogy".|
|6||The King's Demons||Terence Dudley||2||First appearance of Kamelion. Re-appearance of the Master.|
- The Fifth Doctor - Peter Davison
- Tegan Jovanka - Janet Fielding
- Nyssa - Sarah Sutton
- Turlough - Mark Strickson
- The Black Guardian - Valentine Dyall
- The Castellan — Paul Jerricho
- Brigadier Lethbridge-Stewart – Nicholas Courtney
- The White Guardian – Cyril Luckham
- The Master - Anthony Ainley
- John of England/Kamelion - Gerald Flood
- Borusa — Leonard Sachs
- Chancellor Thalia — Elspet Gray
- Councillor Hedin — Michael Gough
- Cardinal Zorac — Max Harvey
- Commander Maxil — Colin Baker
- Lon - Martin Clunes
- Ambril - John Carson
- Tanha - Colette O'Neil
- Chela - Johnathon Morris
- Ibbotson - Stephen Garlick
- Kari - Liza Goddard
- Olvir - Dominic Guard
- Inga - Rachel Weaver
- Eirak - Martin Potter
- Striker – Keith Barron
- Marriner - Christopher Brown
- Wrack – Lynda Baron
- Ranulf Fitzwilliam - Frank Windsor
- Isabella Fitzwilliam - Isla Blair
Stories set during this season
- AUDIO: Omega (immediately after Arc of Infinity)
- AUDIO: The Burning Prince (between Arc of Infinity and Snakedance)
- AUDIO: The Elite (between Arc of Infinity and Snakedance)
- AUDIO: Hexagora (between Arc of Infinity and Snakedance)
- AUDIO: The Children of Seth (between Arc of Infinity and Snakedance)
- PROSE: Fear of the Dark (between Arc of Infinity and Snakedance)
- PROSE: Zeta Major (between Arc of Infinity and Snakedance)
- PROSE: The Sands of Time (between Arc of Infinity and Snakedance)
- PROSE: Goth Opera (between Snakedance and Mawdryn Undead)
- AUDIO: Freakshow (between Enlightenment and The King's Demons)
- AUDIO: Cobwebs (between Enlightenment and The King's Demons)
- AUDIO: The Whispering Forest (between Enlightenment and The King's Demons)
- AUDIO: The Cradle of the Snake (between Enlightenment and The King's Demons)
- AUDIO: Heroes of Sontar (between Enlightenment and The King's Demons)
- AUDIO: Kiss of Death (between Enlightenment and The King's Demons)
- AUDIO: Rat Trap (between Enlightenment and The King's Demons)
- AUDIO: The Emerald Tiger (between Enlightenment and The King's Demons)
- AUDIO: The Jupiter Conjunction (between Enlightenment and The King's Demons)
- AUDIO: The Butcher of Brisbane (between Enlightenment and The King's Demons)
- PROSE: The Crystal Bucephalus (between The King's Demons and The Five Doctors)
Adaptations and merchandising
- Arc of Infinity
- Mawdryn Undead
- The King's Demons/The Five Doctors (extended version)
All serials of season 20 were released individually in between 1999 and 2011, with The Five Doctors being the first ever serial released on DVD.
|Serial name|| Number and duration|
|R2 release date||R4 release date||R1 release date|
| Arc of Infinity|
Only available as part of the Time-Flight/Arc of Infinity box set in Regions 2 and 4.
Only available individually in Region 1.
|4 × 25 min.||6 August 2007||5 September 2007||6 November 2007|
Only available as part of the Mara Tales box set in Regions 2 and 4.
Only available individually in Region 1.
|4 × 25 min.||7 March 2011||7 April 2011||12 April 2011|
| Black Guardian Trilogy: |
Mawdryn Undead (4 episodes)
Terminus (4 episodes)
Enlightenment (4 episodes)
| 12 × 25 min.|
1 × 75 min.
(Enlightenment Special Edition)
|10 August 2009||5 November 2009||3 November 2009|
| The King's Demons|
Only available as part of the Kamelion Tales box set in Regions 2 and 4.
Only available individually in Region 1.
|2 × 25 min.||14 June 2010||5 August 2010||7 September 2010|
|The Five Doctors – Special Edition|| 1 × 100 min.|
|1 November 1999||9 October 2000||11 September 2001|
|The Five Doctors – 25th Anniversary Edition|| 1 × 90 min.|
1 × 100 min.
|3 March 2008||8 May 2008||5 August 2008|