"Logopolis" is the final story for Tom Baker as the Fourth Doctor - his last Doctor Who story after seven years – and the introduction of The Doctor’s new companion Tegan Jovanka, played by Janet Fielding) whilst Nyssa, played by Sarah Sutton and seen in previous story "The Keeper of Traken", returns and joins The Doctor as a companion.
This story picks up soon after the events of "The Keeper of Traken", at the end of which The Master secured a fourteenth incarnation by killing Nyssa’s father Tremas and stealing his body.
Because Script Editor Christopher H Bidmead had been having problems bringing suitable new writers onto Doctor Who, and because he had found the job of script editing very trying, he decided to leave the show at the end of this story, but reluctantly agreed to write the season’s finale himself.
Christopher H Bidmead retained his ties to the show contributing scripts for the Fifth Doctor stories "Castrovalva" and "Frontios". Two further submissions, "In the Hollows of Time" and "Pinacotheca" - were abandoned during the mid-Eighties. Christopher H Bidmead also novelised all three of his televised Doctor Who stories for Target Books.
The Director assigned to this story was Peter Grimwade, who had recently completed "Full Circle".
It was decided only late during production that Nyssa would become a continuing character, so the other new companion, Tegan, was actually cast first; Nyssa does not appear until the second episode and so is not credited for the first episode.
With the recent departure of both Romana and K9 from the show Producer John Nathan-Turner and Script Editor Christopher H Bidmead were keen to find another companion to accompany The Doctor. At the time this story was being produced the character of Nyssa, who had appeared in the previous story "The Keeper of Traken", had not become a regular character.
The idea for The Doctor to have an Australian companion was in the hope that it would make the Australian Broadcasting Company's potential investment in Doctor Who more palatable. Despite this ABC eventually confirmed that they were not interested in a Doctor Who co-production deal with the BBC.John Nathan-Turner and Christopher H Bidmead envisioned the new companion as a bolshy air hostess who would be willing to stand up to The Doctor, but whose forthrightness would privately mask her lack of self-confidence.The name ‘Tegan Jovanka’ came about by accident as John Nathan-Turner suggested two names for the character: Tegan (a Celtic name which John Nathan-Turner selected as homage to the niece of an Australian friend) and Jovanka (inspired by Jovanka Broz, the wife of Yugoslav President Josip Broz Tito). Christopher H Bidmead however, inadvertently interpreted ‘Tegan Jovanka’ as the new companion’s full name, and the error stuck.
The actress chosen to play Tegan was Australian, Janet Fielding who had been recommended to John Nathan-Turner by a friend at the Actors’ Alliance who reckoned that Janet Fielding was a perfect fit to play ‘a bossy Australian’. Janet Fielding had travelled to England in the late Seventies and had worked in theatre before securing a small role in Hammer House of Horror.
The Watcher was played by actor Adrian Gibbs, who was not credited in the Radio Times or on screen.
This story is the second of three stories resurrecting The Doctor's Time Lord arch nemesis, The Master, which was used to bridge the transition from Tom Baker’s version of The Doctor to his successor. The first story in this trilogy was "The Keeper of Traken" and would conclude with the 1981 Fifth Doctor story "Castrovalva" – the story that started Season Nineteen.
This is one of the very first instances of a Doctor Who season having an overall story arc leading up to the season finale. This would become standard practice from 2005 onwards.
This story also concludes a long thread over the preceding season, discussing entropy. In particular, "Logopolis" serves as punctuation to the overarching events of the earlier "E-Space Trilogy".
The exact date of 28 February 1981 for this story is set in the 1981 Fifth Doctor story "Four to Doomsday", as The Doctor is trying to get Tegan to Heathrow in time for her flight. Therefore "Logopolis" and "Four to Doomsday" both happen on the same date. This synchronicity is also shared by the 1966 First Doctor story "The War Machines", the 1967 Second Doctor story "The Faceless Ones", and the first episode of the 1967 Second Doctor story "The Evil of the Daleks", which all occur on the same, unspecified, date in 1966.
The Police Box that The Doctor materialises the TARDIS around, in the first episode, was intended to be the one located at the Barnet bypass, which at the time was one of the last of police boxes in the Metropolitan Police District still in its original location, though it had ceased functioning in the seventies. However, due to it falling into disrepair it was removed in 1981 just prior to the filming of this story. Therefore the TARDIS prop, that had been used until the end of Season Seventeen and which had been placed in storage, was summoned back for use in these sequences.
The lay-by seen at the start of this story was filmed on the southbound side of the A413 Amersham Road, Denham near Gerrards Cross. The lay-by is still there but the M25 motorway now bridges the road where the scene was filmed.
The Watcher appears for the first and only time - a wraith-like intermediate stage between The Doctor’s fourth and fifth incarnations.
The exact nature of the information given to The Doctor and, later, Adric in unheard conversation with The Watcher is never revealed.
After picking up Adric and Nyssa, the Watcher disconnects ‘the entire co-ordinate sub-system’ of the TARDIS, which takes it ‘out of time and space’ - a similar manoeuvre to that seen in the 1968 Second Doctor story "The Mind Robber".
The mystery surrounding the Watcher was felt to be a crucial element to hold the viewers’ interest, and so it was decided to hold off The Master’s first onscreen appearance until episode three, in order to make viewers wonder if the Watcher might actually be the evil Time Lord.
Although The Master does not appear until the third episode, his laughter can be heard in the first two episodes and Anthony Ainley is credited accordingly.
The Master suggests that the Time Lords will not approve of The Doctor’s alliance with him and will cut all ties to him, yet this is never mentioned in any of The Doctor’s latter dealings with them. The DVD information text suggests that this is Christopher H Bidmead’s attempt to write the Time Lords (and the show’s increasingly complex backstory) out of the show altogether, but this was never carried through in subsequent stories.
The Master’s TARDIS is seen disguised as a police box, a tree and an ionic column.
Several elements of this story carry over into "Castrovalva", such as the theme of recursion. In this story this is when The Doctor’s TARDIS materialises around The Master’s TARDIS, thereby creating a recursive loop. A similar process occured in "The Time Monster", yet it does not happen when the TARDIS materialises inside Professor Chronotis’s rooms (actually his TARDIS in disguise) in the untelevised Season Seventeen story "Shada".
There are references to the TARDIS’ faulty Chameleon Circuit and a demonstration of how it could function. The Chameleon Circuit was previously referred to in the 1965 First Doctor story "The Time Meddler", under the name ‘camouflage unit’.
Romana’s room is seen (containing visual references to previous stories, notably "Meglos" and "City of Death"). This is when The Doctor and Adric look at Romana’s now deserted room in the TARDIS and talk about her recent departure in "Warriors' Gate" and decide to postpone their trip to Gallifrey, where The Doctor had been under orders to return his former companion. The Doctor eventually jettisons Romana’s room to escape the pull of The Master’s TARDIS.
The TARDIS cloisters are seen for the first time. The Cloister Bell is described as ‘a sort of communication device reserved for wild catastrophes and sudden calls to man the battle stations’. The Doctor states that the TARDIS was in Gallifrey for repairs when he ‘borrowed’ her stating ‘There were rather pressing reasons at the time'.
According to Christopher H Bidmead, the Logopolitans employ a hexadecimal, or base-16, numerical system, a real system commonly used in computer programming. When Adric and the Monitor read strings of numbers and letters, the letters are actually the numbers between 10 and 15, expressed as single digits.
It is revealed that the Logopolitans are vital to the stability of the Universe. They discovered long ago that the Universe had passed the natural point of total collapse and so used block transfer computation to create Charged Vacuum Emboitements into other universes. The Master’s interference with Logopolis leads to the unravelling of the causal nexus (‘You're interfering with cause and effect’).
The entropy field caused by the destruction of Logopolis also destroys a portion of the universe (Traken and Mettula Orionsis (Traken’s star) are mentioned. It is though fair to assume that other inhabited planets would have suffered the same fate). The Doctor’s transmission of the Logopolis program saves the rest of the Universe, starting with the constellation of Cassiopeia (see the "The Seeds of Doom").
The key plot point of shunting excess entropy into another universe was previously used in Isaac Asimov’s novel "The Gods Themselves".
This story has arguably the largest number of deaths of any Doctor Who story - albeit mostly off-camera - with a significant portion of the entire universe swallowed up by the wave of entropy. At the very least, the Traken Union is destroyed, which would put the death toll in the billions and making The Master a mass murderer of unprecedented proportions. The Last Great Time War potentially had a higher body count, however, even were a death toll to be given, this event occurred off-screen.
The BBC Books’ The Past Doctors Stories novel "The Quantum Archangel", by Craig Hinton, briefly shows an alternate timeline where the destruction of Logopolis did result in the death of the universe. The Doctor Who Unbound audio story "He Jests at Scars... " depicts a timeline in which the Valeyard attempts to undo the events of this story by destroying Logopolis before the Fourth Doctor visited it.
The Central Registry on Logopolis is a duplicate of the Pharos Project on Earth.
The location scenes at the Pharos Project were filmed at a BBC receiving station in Crowsley Park, with a model standing in for the radio telescope and not the Lovell Telescope at Jodrell Bank.
After The Doctor plummeted to his doom from the Pharos Project radio telescope it afforded his companions Adric, Nyssa and new friend Tegan Jovanka the ability to say goodbye as he regenerated.
After his fall, The Doctor regenerates by merging with the Watcher, who is a future projection of The Doctor. This is similar to that of his mentor K’Anpo Rinpoche (in the form of Cho-Je) in the 1974 Third Doctor story "Planet of the Spiders" - The Doctor’s previous regeneration story. This would seem to indicate that a Watcher can merge with another person entirely. A similar Watcher is present in the Fifth Doctor’s mindscape in the "Winter" segment of the Big Finish Productions audio story, "Circular Time".
The lead up to The Doctor’s regeneration, at the conclusion of this story, included two compilations of clips featuring old enemies and friends of The Doctor. John Nathan-Turner was keen to pay tribute to the show’s fanbase, and felt that including these flashbacks – which had never before attempted during the show before – would be exactly what fans of the show would enjoy.
The enemies seen in the first part of this sequence were: a skeletal version of The Master ("The Deadly Assassin" part one), a Dalek ("Destiny of the Daleks" episode four), the Pirate Captain ("The Pirate Planet" part four), a Cyberman ("Revenge of the Cybermen" part three), Davros ("Genesis of the Daleks" part five), a Sontaran ("The Invasion of Time" part five), a Zygon ("Terror of the Zygons" part three) and The Black Guardian ("The Armageddon Factor" part six).
The companions seen in the second part of this sequence were: Sarah Jane Smith ("Terror of the Zygons" part two), Harry Sullivan ("The Sontaran Experiment" part two), The Brigadier ("Invasion of the Dinosaurs" part two), Leela ("The Robots of Death" part one), K9 ("The Armageddon Factor" part two), the first incarnation of Romana ("The Stones of Blood" part one) and the second incarnation of Romana ("Full Circle" part one).
The music from the regeneration scene was later reused for the regeneration of Rowan Atkinson’s Doctor in the 1999 Comic Relief special "Doctor Who and the Curse of Fatal Death".
This sequence was repeated with different music and overdubs as a pre-title sequence before the Fifth Doctor’s first story "Castrovalva".
This story contains a number of errors: When the TARDIS is shrunk, it is first seen without the ‘public use’ placard. Later, as it is wheeled away, the plaque is there; At the beginning of the second episode, when The Doctor and Adric are going back to the TARDIS to escape the policemen, The Doctor opens the door to the right, however Adric goes through a door that is open to the left; Also in the second episode Adric has wet trousers when leaving the TARDIS (which he acquires later when faking his bike accident); When The Master puts the bracelet onto Nyssa's wrist, part of it falls off; In the fourth episode, when The Master enters his TARDIS, his shadow stays after it dematerialises; The Master looking out of the cabin doorway is very obviously a CSO’d still frame; The Doctor’s flashback of The Master is of him saying ‘Predictable as ever, Doctor’ from episode one of the 1976 story "The Deadly Assassin", but The Doctor was not actually present when The Master said that.
This is the last televised story to feature Tom Baker as the Fourth Doctor. He did though appear in the Twentieth Anniversary special "The Five Doctors", but this was only in the form of footage from the uncompleted "Shada".
Tom Baker’s involvement with Doctor Who, after his departure, consisted primarily of a guest shot in the Thirtieth Anniversary Children In Need special "Dimensions in Time", in 1993, as well as his narration of the Season Seventeen cancelled story "Shada" and "The Tom Baker Years" documentary. He first post-Doctor Who role was as Sherlock Holmes in The Hound of the Baskervilles. Tom Baker soon found himself once again in demand, appearing and on television in programmes including Blackadder, The Chronicles of Narnia: The Silver Chair, Medics, the revival of Randall & Hopkirk (Deceased), Monarch of the Glen and as the narrator for Little Britain.
Tom Baker has also narrated a number of Target novelisations of his stories for a range of talking books from BBC Audio. However, despite persistent appeals over the years from Big Finish Productions, Tom Baker has so far refused to record a new appearance as the Fourth Doctor for their range of Doctor Who audio plays. He has though returned to the role for the BBC Hornets’ Nest audio stories, in 2009, and the Demon Quest audio stories, in 2010.
Tom Baker currently holds the record for longest tenure (seven consecutive years) as The Doctor on-screen and he appeared in a total of 178 episodes in 42 stories - although both Sylvester McCoy and Paul McGann would later be considered the ‘current Doctor’ for about nine years each but this was due to the show being off-air for most of the time during their time in the show.
The role of the Fifth Doctor was offered to Peter Davison. One of John Nathan-Turner’s most significant assignments prior to becoming Doctor Who’s producer had been as Production Unit Manager on All Creatures Great and Small, which had already influenced a number of his choices for Doctor Who writers and directors. John Nathan-Turner became aware of a publicity photo of a charity cricket match which included Peter Davison - who had played the part of Tristan Farnon in 65 episodes between 1978 and 1990 - and he realised that the younger and fair-haired Peter Davison was a striking visual contrast to Tom Baker also John Nathan-Turner hoped that fan’s of Peter Davison might follow him to Doctor Who.
The closing titles sequence, used on the final episode, was recompiled with Tom Baker’s face removed from the closing credits and with Peter Davison’s face added for the following story, "Castrovalva".
The final episode of this story was the last time, for the next 24 years, that the lead character was listed in the credits as ‘Doctor Who’ (thus making it the only time Peter Davison was credited as ‘Doctor Who’). Beginning with the next story, "Castrovalva", until the show’s cancellation in 1989, the lead character was credited simply as ‘The Doctor’. The 1996 television film did not have an on-screen credit for the Eighth Doctor, but listed the Seventh Doctor as the ‘Old Doctor’. The 2005 re-launch returned the credit to ‘Doctor Who’ until David Tennant, who played the Tenth Doctor, requested that it reverted back again to ‘The Doctor’ in the 2005 story "The Christmas Invasion".
The fourth episode 4 was the first to credit two actors as playing the lead part when a regeneration scene was involved. This also occurred at the end of the fourth episode of the 1984 story "The Caves of Androzani". In both instances, Peter Davison was billed second.
The two actors playing the lead part were also both credited in the final episodes of the 2005 Ninth Doctor to Tenth Doctor regeneration story "Bad Wolf/The Parting of the Ways" and the 2009/10 Tenth Doctor to Eleventh Doctor regeneration story "The End of Time".
Barry Letts departed at the end of this story as Executive Producer (although he also did some work on the 1982 Fifth Doctor story "Four to Doomsday", the first story of the show’s nineteenth recording block) as it was felt that John Nathan-Turner had enough experience to guide Doctor Who without Barry Letts’ supervision and so the position of Executive Producer was abandoned.
This story was repeated on BBC2 in November/December 1981, as part of "The Five Faces of Doctor Who".
Peter Davison's first appearance as the Fifth Doctor.
The introduction of companion Tegan Jovanka played by Janet Fielding.
The first trip in the TARDIS for new companion Nyssa played by Sarah Sutton.
The first Doctor Who story where a citizen from Australia travelled with The Doctor.
The first story to show the TARDIS cloisters.
The first Doctor Who story to be written by Christopher H Bidmead.