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24 September 2014

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Production Code: 5V

First Transmitted

1 - 28/02/1981 17:10

2 - 07/03/1981 17:10

3 - 14/03/1981 17:10

4 - 21/03/1981 17:10


The Doctor takes Adric and a young air hostess named Tegan Jovanka, who has come aboard the TARDIS by accident, to the planet Logopolis, home of a race of mathematicians whose help he hopes to enlist in reconfiguring the outer shell of the TARDIS.

The mysterious, wraith-like Watcher brings Nyssa from Traken to join them and warns of impending danger - something that is borne out as the Master arrives and kills a number of the Logopolitans.

The Logopolitans' leader, the Monitor, reveals that the universe passed its normal point of heat death long ago and has been preserved only by his people's calculations, which - by way of a signal beamed from a perfect copy of the Pharos Project radio telescope on Earth - have kept open numerous CVEs through which the excess entropy can drain.

This process has now been halted by the Master's interference, and the Doctor is forced to join forces with his arch-enemy in order to save the universe.

Their plan is to use the real Pharos Project to transmit a copy of the Logopolitan program and thus keep open the CVEs, but the Master seizes the opportunity to blackmail the peoples of the universe by threatening them with destruction unless they agree to his demands.

In foiling this scheme the Doctor falls from the gantry of the radio telescope. As he lies injured on the ground the Watcher appears again and merges with the Doctor as he regenerates.

Episode Endings

The Doctor finds the police investigating Tegan's abandoned sports car. A Detective Inspector asks him to explain the presence in the car of two shrunken bodies: a policeman and Tegan's aunt Vanessa. The Doctor realises that the Master has escaped from Traken and must be somewhere near.

The Doctor attempts to reconfigure the TARDIS but it begins to shrink instead. As his friends watch from outside, the ship gets smaller and smaller.

The Doctor decides to collaborate with the Master to save the universe from entropy. He bundles Adric, Nyssa and Tegan into the TARDIS, then he and the Master shake hands on their agreement to work together. 'One last hope,' says the Doctor.

The Doctor goes out onto the gantry of the radio telescope and disconnects the power cable. The Master causes the gantry to move and the Doctor, unable to cling on to the cable, falls to the ground below. He is joined by Adric, Nyssa and Tegan who look on as the mysterious Watcher merges with him. The end result is a new incarnation of the Doctor, who sits up.


Maxwell's second law of thermodynamics.

'Godel, Escher, Bach' by Douglas Hofstadter.

Sherlock Holmes ('The Final Problem').

The Doctor misquotes his 'old friend' Thomas Huxley ('the cheese board is the world...').

Dialogue Triumphs

The Doctor : [Speaking of the Master] "He must have known I was going to fix the chameleon circuit."

Adric : "He read your mind?"

The Doctor : "He's a Time Lord! In many ways we have the same mind."

The Doctor : "Never guess. Unless you have to. There's enough uncertainty in the universe as it is."

The Doctor : "It's the end... but the moment has been prepared for."


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. ('There were rather pressing reasons at the time'.) There are references to the TARDIS' (faulty) chameleon circuit.

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 in The Mind Robber]. Romana's room is seen (containing visual references to previous stories, notably Meglos and City of Death) before it is jettisoned.

The Doctor says that Romana has 'broken the cardinal rule of Gallifrey. She has become involved, and in a pretty permanent sort of way'.

Adric asks if the Master read the Doctor's mind, to which the Doctor replies 'He's a Time Lord. In many ways we have the same mind.' [See The Invisible Enemy.] The Master's TARDIS disguises itself as a police box, a tree and an ionic column at various times.

After his fall, the Doctor regenerates by merging with the Watcher, who is a future projection of the Doctor [similar to Cho-Je/K'Anpo-Rinpoche regeneration in Planet of the Spiders. The Keeper of Traken and 'The Trial of a Time Lord' would seem to indicate that a Watcher can merge with another person entirely.]

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 [though it is 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 Seeds of Doom) [for once a reasonable use of 'constellation'].

Earth is said to be in Sector 8023 of 'the third quadrant'.




The TARDIS Scanner


Earth, Logopolis, 28 February 1981.



The Doctor has been to Logopolis before, when the Logopolitans offered to do the chameleon conversion for him. He is a friend of Thomas Huxley's.


The Watcher appears for the first and only time - a wraith-like intermediate stage between the Doctor's fourth and fifth incarnations.

Two sets of clips from previous Doctor Who stories are included in flashback sequences leading up to the Doctor's regeneration in Part Four.

An electronic effect is used on Part Four's closing title sequence to blur the usual image of Tom Baker's face.


On Logopolis, sonic projectors are said to 'create a temporary zone of stasis'. The mathematics of block transfer computation is a way of modelling space/time events through pure calculation. The Doctor asks Adric to 'fold back the Omega configurations'. The Master suggests 'we reconfigure our two TARDISes into time cone inverters... We create a stable safe zone by applying temporal inversion isometry to as much of space/time as we can isolate.'


Why is there a litter bin next to the 'Take Your Litter Home' sign in episode one?

Why does the policeman take the doll-like corpses so seriously?

In episode two, 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.

Entropy is green.

In episode four, 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.

He also nods Tegan her cue to notice that the Monitor is dying.

Fashion Victim

Aunt Vanessa's coat.

Tegan's stockings with seams (bleurgh).

Cast & Crew


The Doctor - Tom Baker

The Doctor - Peter Davison

Adric - Matthew Waterhouse

Nyssa - Sarah Sutton

Tegan - Janet Fielding

Aunt Vanessa - Dolore Whiteman

Detective Inspector - Tom Georgeson

Security Guard - Christopher Hurst

The Master - Anthony Ainley

The Monitor - John Fraser


Director - Peter Grimwade

Assistant Floor Manager - Val McCrimmon

Costumes - June Hudson

Designer - Malcolm Thornton

Executive Producer - Barry Letts

Film Cameraman - Peter Hall

Film Editor - Paul Humfress

Incidental Music - Paddy Kingsland

Make-Up - Dorka Nieradzik

Producer - John Nathan-Turner

Production Associate - Angela Smith

Production Manager - Margot Heyhoe

Script Editor - Christopher H Bidmead

Special Sounds - Dick Mills

Studio Lighting - Henry Barber

Studio Sound - John Holmes

Title Music - Ron Grainer and the BBC Radiophonic Workshop, arranged by Peter Howell

Visual Effects - John Horton

Writer - Christopher H Bidmead

Bottom Line - from The Discontinuity Guide

'It's the end... but the moment has been prepared for.' A funereal atmosphere marbles Logopolis thanks to the exit of Tom Baker. It's a magnificent farewell, although some of the elements of Logopolis seem baffling now (especially the Doctor's plan to flush out the Master).

Still, Logopolis continued the upbeat qualitative trend of the 18th season and pointed the way forward for the three years of renaissance that were to come. Not the easiest story to watch, but certainly one of the most emotional.

Analysis - from Doctor Who, the Television Companion

Logopolis tries hard to be the epic tale that it really needs to be as the concluding story of Tom Baker's extraordinary seven year tenure as the Doctor, and for the most part it succeeds.

Script editor Christopher H Bidmead made it a top priority to introduce some harder science into Doctor Who and move away from what he saw as the unduly fantasy-based approach of the previous few years; in the self-written Logopolis he takes this reliance on scientific concepts to its furthest extreme, as Justin Richards pointed out in Aggedor Issue 5 in 1983: 'There can be little doubt that Logopolis boasted one of the best, and by that I mean deepest, yet still accessible as basic entertainment, scripts of the series; the philosophical and scientific theories and arguments are presented and questioned at a speed which the Logopolitan mathematicians themselves would find staggering - the argument for and against causality which runs through the story is made overt by passing references to Thomas Huxley and the causal nexus, while the computer nature of Logopolis itself is referred to in casual lines about subroutines and Algol. The brain-like structure of the model [of Logopolis]... is not made as obvious as perhaps it could be.'

It has been argued, however, that the Logopolitans' power to create any event in space and time simply by reciting a string of mathematical expressions could be more properly described in another way. Jan Vincent-Rudzki, writing in Baker's Best in 1981, asserted: '[We] have in Logopolis a race of wizards practicing magic, something the Doctor has always pooh-poohed, yet nobody... seemed to realise this or be particularly impressed. What should have been an amazing discovery for the Doctor was glossed over so quickly, when it should have been marvelled at. This was one of the main faults of the final [story]; people just did not react to situations in a normal manner... when thrust into an alien situation they became like cardboard cut-outs whose mouths opened to say the words.'

There are also, it must be pointed out, one or two staggeringly unscientific ideas in the story, such as the Doctor's proposal to open the TARDIS doors underwater and thereby 'flush out' the Master (strangely overlooking the fact that both he and Adric would undoubtedly be killed in the process) and, in Part Four, the Master's attempt to broadcast to the 'peoples of the universe' using what looks like a transistor radio. In fact, seen here in his first full story, the new Master unfortunately comes across as merely a poor copy of the character portrayed by Roger Delgado in the seventies. 'After all the Master's evil laughter I half expected him to twirl his moustache,' commented Vincent-Rudzki, 'but thankfully the corn did not go that far... Anthony Ainley seems a good choice for the Master in a Delgado mould, but I think it would have been better to give him a more definitive variation of the Master's character, as the Doctor has when he regenerates. Likewise, if this was the Delgado version reborn, then why did he wear that silly suit that made him look like a penguin?'

These faults notwithstanding, Logopolis does undoubtedly fulfil its main function of providing a suitable lead-in to the Doctor's regeneration, as Peter Anghelides observed in Oracle Volume 3 Number 11/12, dated Christmas 1981: 'One way in which Logopolis continually entertained us was, strangely, by baffling us. However, this was not a blinding with science, but rather an increasing puzzlement as to the continuing plotline. Who is the distant stranger? How is the Master manipulating the Doctor's fortune? What is the "single great secret" of Logopolis which is the Master's goal?

These are all admirably sustained throughout the story, until at the apposite moment they are devastatingly explained, and we are faced (as is the Doctor) with the prospect of the destruction of the universe. So skilfully is the problem introduced that I think we all felt, for once, that the Doctor faced real defeat, rather than believing that "he is on TV next week, so he can't get killed". To all intents and purposes, the Doctor dies! He is then born again, but we can reflect wryly that for once the Doctor has tasted true defeat, with the Master's continued (and renewed) existence only highlighting the Doctor's inadequacy (being forced to regenerate after the fall).'

Mark Woodward, writing in Web Planet Number 8, dated August 1981, summed up the thoughts of many: 'I had an overwhelming feeling of apprehension as the last seconds of this story ticked relentlessly away, the end of the Doctor's fourth incarnation drawing ever nearer, [his] past life flashing before his weary eyes as he clung desperately to the cable. Resolved to his destiny, Earth's gravity claimed his seemingly fragile form as he plunged to his doom... He did not scream as he fell. Then he uttered his final words... and I suddenly realised I was going to miss him.'

It is only with hindsight that one can see just how much Baker was missed. Certainly as far the series' popularity with the general viewing public was concerned, this story would prove to be a turning point.

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This episode guide is made up of the text of The Discontinuity Guide by Paul Cornell, Martin Day and Keith Topping, and Doctor Who: The Television Companion by David J. Howe and Stephen James Walker.

The Discontinuity Guide © Paul Cornell, Martin Day and Keith Topping 1995.
Doctor Who: The Television Companion © David J Howe and Stephen James Walker 1998, 2003.

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