The Deadly Assassin (TV story)

The Deadly Assassin was the third serial of season 14 of Doctor Who. It was the only televised story in the original run of Doctor Who to feature the Doctor without a companion. Tom Baker had told Philip Hinchcliffe he could hold the show on his own. With this story already in place, it was seen as a pilot for such companion-less stories. However, it was deemed that a companion was a necessary feature of the show.

This serial saw the return of the Doctor's nemesis, the Master, but in a heavily decayed state played by Peter Pratt. Roger Delgado had died in an automobile accident three years earlier, requiring a new actor to take his place. Afterwards, the Master became subject to a change in appearance and other changes as needed when an actor replaced the role, much like the Doctor, although, from an in-universe perspective, which change of actors should be considered a change of "incarnation" is far less clear-cut.

Narratively, this serial introduced several aspects and notable figures of Time Lord society which were used, or referenced again, including the Matrix, Time Lord Chapters, Time Lord headdresses and robes, Borusa and of course Rassilon. It also introduced the restriction of a Time Lord to a finite limit of twelve regenerations, allowing a maximum of thirteen incarnations, after which a Time Lord would suffer permanent death.

Later stories revealed that there are exceptions to the rule, such as the Master, who, after exhausting his original cycle, stealing a non-Gallifreyan body (TV: The Keeper of Traken) and being executed by the Daleks, (TV: Doctor Who) was resurrected by the Time Lords to fight in the Last Great Time War, gaining a new cycle in the process. (TV: Utopia, The Sound of Drums, The Doctor Falls), and the Doctor, who was granted a new regeneration cycle when his final incarnation reached the point of death. (TV: The Time of the Doctor)

In 2020, The Deadly Assassin became part of the Time Lord Victorious multimedia event.

Synopsis
Through the millennia, the Time Lords of Gallifrey led a life of peace and ordered calm, protected against all threats from lesser civilisations by their great power. But this was to change. Suddenly and terribly, the Time Lords faced the most dangerous crisis in their long history...

Part one
Having dropped off former companion Sarah Jane Smith back home on Earth, the Fourth Doctor heads to Gallifrey in answer to the Time Lords' summons. On the way, he is struck by a premonition in which he seems to assassinate the Time Lord President from a gallery overlooking the Panopticon.

The TARDIS lands in the security area of the Citadel. Commander Hilred immediately impounds it and the Castellan Spandrell orders the arrest of its owner, who is registered as a wanted criminal. The Doctor leaves a note (written in Gallifreyan script, and bearing an image of the Seal of Rassilon) on the console warning of his premonition and sneaks out of the TARDIS into the Citadel. He is cornered by a guard, who is shot dead by an unknown assailant, who flees before the Doctor can confront them.

The arrival of an unregistered TARDIS in a high-security area raises the tension of an already tense day — the President is resigning and is about to name his successor. The Castellan berates Hildred for his incompetence in letting the Doctor, a renegade who apparently is also a murderer, run loose in the capitol.

Hildred transducts the TARDIS into the capitol's museum, unaware the Doctor has sneaked back inside. Meanwhile, his movements are being monitored by a dark, robed figure and an unknown associate.

The Doctor infiltrates the resignation announcement by stealing a Time Lord's ceremonial robes. While trying to remain incognito in the crowded floor, he encounters an old classmate, Runcible, who is now a commentator for the local news channel Public Register Video and preparing his broadcast from the Panopticon floor. Runcible greets the Doctor coolly, while waiting for a signal from a camera operator in the gallery — who strangely does not answer. The Doctor looks up to the gallery and is horrified to see a staser rifle fixed to the railing near the unattended camera. He causes a commotion as he charges through the room.

As the President enters and stands at the dais, the Doctor grabs the staser rifle, aims and fires. The President falls down dead...

Part two
The Doctor is quickly apprehended by security. The assassination has thrown Gallifrey into a constitutional crisis because the President died before he could name his successor. Chancellor Goth, thought to have been the most likely successor, calls for prompt elections and opts to stand as a candidate. Goth also urges the Doctor's swift trial and execution.

At the trial, Goth's prosecution moves swiftly. The Doctor, however, invokes Article 17 of the Gallifreyan Constitution, naming himself as a candidate for President. Under it, he cannot be denied the right to make his claim. Goth is outraged, but Cardinal acknowledges that the article gives him protection. He is grudgingly given forty-eight hours to prove his innocence.

The robed figure is told by his associate of the Doctor's use of the constitutional loophole. He has anticipated this. The figure is shown as a horribly disfigured and decaying husk.

The Doctor attempts to convince Spandrell and Coordinator Engin of his innocence; his shot was intended for the actual assassin, who stood in the crowd on the Panopticon floor. Someone is going to great lengths to frame him. He notes that the sights had been fixed on the rifle to intentionally throw off his aim. Spandrell confirms this by aiming at a target — a large Seal of Rassilon symbol on the wall — himself; he begins to believe the Doctor. They find the Doctor's original blast mark on the wall. The Doctor realises the gallery camera would have recorded the actual assassin. Runcible screams with horror when he looks into the camera barrel.

Running to the gallery, they find the camera barrel empty except for the miniaturised corpse of the cameraman. The Doctor recognises this as the work of his arch enemy, the Master, and reasons that he has returned to Gallifrey for a final showdown. Runcible goes to fetch the recordings, but when he returns, he falls with a knife protruding from his back.

Spandrell and Engin cannot comprehend why there is no biodata extract for the Master in the APC Net (aka the Matrix). This is a network of past and present Time Lord minds that acts as an enormous database and future forecaster. The Doctor decides there must be an unauthorised second access point into the Matrix. The Master used this to forecast the assassination into his mind and then wipe all trace from the Matrix. He reasons that either the Master or the assassin working with him must be inside the Matrix. Despite the stern warning from Engin, he interfaces with the Matrix to find him.

The Doctor finds himself in a vast, rapidly shifting terrain, the domain of the assassin. The two engage in a pitched battle of wills. The assassin has the definite advantage of having created the virtual reality world inside the Matrix.

The Doctor finds himself in a jungle. He steps on a railway track, and his foot becomes stuck in the rails as the points change. He looks up to see a masked man driving a train towards him...

Part three
The Doctor prepares for impact, but nothing happens. He gets his foot out and moves on. The Doctor evades the many pitfalls laid for him inside the Matrix. These include being strafed by a biplane and tracked by the assassin. His physical body, still in the APC room is enduring a terrible and potentially lethal strain. Meanwhile, the assassin is finding the battle of wills extremely taxing as well. The Master increases the power, despite the assassin's plea it will kill him. The Doctor begins to turn the tables on his assailant, first by booby-trapping the hunter's equipment, then by avoiding the water poisoned by the assassin. He improvises a blowpipe and shoots a poisoned dart at the assassin, but he is wounded himself. As the Doctor comes closer to winning the conflict, the Master sends one of the chancellor's guards now under his power to the APC room to kill the Doctor. Engin spots the guard, Solis, tampering with the controls. Spandrell shoots Solis to protect the Doctor.

In the Matrix, the Doctor gains the upper hand against the assassin, who reveals himself as Goth. The Doctor tricks Goth into firing his rifle while in a cloud of swamp gas. As the world around them erupts in chaos and flames, Goth seizes the Doctor and holds his head underwater, about to drown him.

Part four
The Doctor throws Goth off and escapes from the Matrix. He revives in Spandrell's office. He informs the shocked Castellan of the assassin's identity. They trace the location of their lair, where they find the Master's lifeless body — he seems to have died of natural causes. Goth, himself near death, admits he was power-hungry and bitter on learning he wasn't to be the President's successor. He had found the dying Master on the planet Tersurus, his body at the end of his regeneration cycle, and brought him to Gallifrey to help him fulfil his scheme. Goth dies before he can reveal just what the Master's plan was.

Cleared of all charges, the Doctor still has lingering doubts and wants to know the Master's plan. He doubts the Master would accept death so easily and reasons that the solution lies in the ceremonial relics given to the President on induction, the Sash and Rod of Rassilon, and researches their links to ancient Gallifreyan mythology.

The Doctor's suspicions are confirmed. The Master has faked his own death. He steals the Sash and Rod, which are the keys to the Eye of Harmony, the heart of a black hole captured by ancient Time Lord Rassilon. It is the source of Time Lord power. The Master seeks the power of the Eye to restart his regeneration cycle, even though Gallifrey would be destroyed by doing so. He uses the Rod to unlock the Eye of Harmony, hidden below the Panopticon floor. This begins to release its energy, which would be channelled through the Sash to rejuvenate him.

The Doctor wrestles with the Master. The ground shakes around them. Before the Master can uncouple the last cable from the Eye, the Doctor pulls him away, and the Master falls through a fissure in the floor. The Doctor reconnects the cables, bringing the crisis to an end.

Borusa is appalled at the damage; half the capital city lies in ruins and countless lives are lost. Even so, he accepts Engin's claim that the Doctor's actions prevented further catastrophe. Recalling their old relationship as teacher and student, Borusa gives the Doctor a grade of 9 out of 10. Spandrell and Engin accompany the Doctor back to the museum, and say their farewells; the Doctor then departs in the TARDIS. Spandrell and Engin then discover that the Master has survived and escaped in his own TARDIS, disguised as a grandfather clock. Spandrell expresses confidence that the Doctor and the Master will cross paths again, and has a feeling the universe is not big enough for the two of them. Before the Master's TARDIS dematerialises, the face of the grandfather clock is replaced by that of the Master, with the sound of his laughter heard over the TARDIS dematerialisation sound...

Cast

 * Doctor Who - Tom Baker
 * The President - Llewellyn Rees
 * Chancellor Goth - Bernard Horsfall
 * Castellan Spandrell - George Pravda
 * Cardinal - Angus MacKay
 * The Master - Peter Pratt
 * Commentator Runcible - Hugh Walters
 * Co-ordinator Engin - Erik Chitty
 * Commander Hilred - Derek Seaton
 * Gold Usher - Maurice Quick
 * Time Lords - John Dawson, Michael Bilton
 * Solis - Peter Mayock
 * Voice - Helen Blatch

Crew

 * Assistant Floor Manager - Linda Graeme
 * Costumes - James Acheson, Joan Ellacott
 * Designer - Roger Murray-Leach
 * Fight Arranger - Terry Walsh
 * Film Cameraman - Fred Hamilton
 * Film Editor - Ian McKendrick
 * Film Sound - Graham Bedwell
 * Incidental Music - Dudley Simpson
 * Make-Up - Jean Williams
 * Producer - Philip Hinchcliffe
 * Production Assistant - Nicholas John
 * Production Unit Manager - Chris D'Oyly-John
 * Special Sounds - Dick Mills
 * Studio Lighting - Brian Clemett
 * Studio Sound - Clive Gifford
 * Theme Arrangement - Delia Derbyshire
 * Title Music - Ron Grainer
 * Visual Effects - Len Hutton, Peter Day

Uncredited crew

 * Assistant Floor Manager - Linda Graeme (INFO: The Deadly Assassin)
 * Booking Assistants - Carol Atterbury, John Holland (INFO: The Deadly Assassin)
 * Contracts Assistant - Nansi Davies (INFO: The Deadly Assassin)
 * Costume Assistant - Brian Hoyle (INFO: The Deadly Assassin)
 * Design Assistant - John Price Jones (INFO: The Deadly Assassin)
 * Director's Assistant - Joan Elliott (INFO: The Deadly Assassin)
 * Electronic Effects - A. J. Mitchell (INFO: The Deadly Assassin)
 * Facilities Assistants - Jennie Betts, Carol Vigurs (INFO: The Deadly Assassin)
 * Film Operatives - Albert Crush, Bob Johnson (INFO: The Deadly Assassin)
 * Film Sound Assistant - Terry Elms (INFO: The Deadly Assassin)
 * Floor Assistant - Philip Livingstone (INFO: The Deadly Assassin)
 * Grams Operator - James Cadnam (INFO: The Deadly Assassin)
 * Grips - Stan Swetman (INFO: The Deadly Assassin)
 * Location Chef - Brian Casey (INFO: The Deadly Assassin)
 * Make-Up Assistants - Hadsera Coouadia, Judith Dalton (INFO: The Deadly Assassin)
 * Script Editor - Robert Holmes (INFO: The Deadly Assassin)
 * Senior Cameraman - Peter Granger (INFO: The Deadly Assassin)
 * Technical Manager - Peter Valentine (INFO: The Deadly Assassin)
 * Visual Effects Assistants - Dave Bezkorowajny, Steven Drewett (INFO: The Deadly Assassin)

Books

 * The Book of the Old Time is mentioned.

The Doctor

 * According to Coordinator Engin, the Doctor's brain "must have an unusually high level of artron energy".

Galaxies

 * The term Mutter's Spiral is used by the Time Lords.

Gallifrey

 * Shobogans are hooligans on Gallifrey.

Gallifreyan technology

 * Applied excitonics is the science used to create the excitonic circuitry the biodata bank of the Time Lords is made of.

Gallifreyan law

 * Article 17 could be invoked to present one's claim for the post of President. No candidate for the presidency could be debarred or restrained from this liberty (with the exception of condemned murderers).
 * Chancellor Goth wished to amend the details of this article once he were elected.

Gallifreyan Chapters

 * Prydonians, the "notoriously devious" sect to whom the Doctor belongs, are colour-coded scarlet and orange.
 * Arcalians wear green.
 * Patrexes wear heliotrope.

Gallifreyan culture

 * The Doctor arrives on Presidential Resignation Day.
 * The Doctor's trial is dated 309906.
 * Runcible appears to use the term "face-lift" as slang for "regeneration".
 * Accused of the assassination of the Lord President, the Doctor faces the possibility of being sentenced to death in a vaporisation chamber.
 * According to Engin, precognition is impossible.

Gallifreyan history

 * References are made to Old Times.

Gallifreyan organisations

 * Security in the Capitol is a duty of the Chancellery Guard.
 * The Celestial Intervention Agency (aka "CIA") are mentioned.

Individual Gallifreyans

 * has recently become a Cardinal.
 * Borusa was a teacher to the First Doctor at the Time Lord Academy. In that age, according to the Doctor, he had stated that truth can be found only in mathematics.

Places

 * The Doctor bought a hookah in a "cash and carry" in Constantinople.

TARDISes

 * The Doctor's TARDIS is a Type 40 protected by a "double curtain trimonic barrier" which requires a cypher indent key.
 * The Master's TARDIS is disguised as a grandfather clock. It dematerialises after the Doctor's TARDIS leaves Gallifrey.

Story notes

 * The story had a working title of The Dangerous Assassin.
 * The title is generally considered a tautology — an assassin is, by definition, deadly. This redundancy was parodied in the spoof The Curse of Fatal Death. However, Robert Holmes denied that the title was tautological, saying, "There are plenty of incompetent assassins." (INFO: The Deadly Assassin)
 * This is the first TV story to feature the Doctor without a companion and the only one during the 1963-89 original series. The 1996 telefilm and revival series featured the Doctor on occasion collaborating with "one-off" companions (such as Donna Noble in The Runaway Bride) and in Midnight, the Doctor has an adventure by himself, away from his companion. All that said, The Deadly Assassin remains unique as the only televised Doctor Who adventure to date in which the Doctor appears but there is no companion or companion-surrogate at all. The episode Heaven Sent also features an entire story with only the Doctor and no companions, but the actress Jenna Coleman appears in the episode as part of the Doctor's mind manifestation.
 * This story features an exclusively male cast, except for the female computer voice provided by Helen Blatch.
 * Helen Blatch (Voice) is uncredited on-screen for part one but credited in Radio Times.
 * This is the first story set entirely on Gallifrey, as well as the first story whose cast is entirely made up of Time Lords and the first televised story in which no human characters appear.
 * This story featured the first use of narration, performed by Tom Baker at the beginning of part one:
 * Through the millennia, the Time Lords of Gallifrey led a life of peace and ordered calm, protected against all threats from lesser civilisations by their great power. But this was to change. Suddenly, and terribly, the Time Lords faced the most dangerous crisis in their long history...
 * This text was also shown as a roller caption, superimposed over the Cloisters set.


 * The biplane used in the Matrix sequences in episode three is a 1949 . The plane used in filming, registration G-AWXZ, was also used in the films and . (INFO: The Deadly Assassin)
 * The Doctor is without companions at the end of the story, making the period between this story and the next one of the few plausible spots during the show's run which allows for placement of any number of additional Doctor Who stories in literature, audio, or comics. This allows the inclusion of companions that are exclusive to these adventures. A similar instance occurred between The Invasion of Time and The Ribos Operation, that one allowing for the inclusion of later developments such as K9.
 * Artistic elements introduced in this story, particularly the Time Lord collars and the Seal of Rassilon, appear on multiple later occasions in stories featuring Time Lords.
 * This story establishes that Time Lords do sometimes use proper names on their homeworld; previous uses have either been aliases or of ambiguous origin such as Morbius; rank-and-file Time Lords seen in television stories like The War Games and The Three Doctors had gone unnamed.
 * This story introduces the iconic character Rassilon, who would be referenced often. Rassilon would be seen via a form of projection in The Five Doctors and in person in The End of Time and Hell Bent. It also greatly expands on the Time Lord society and mythology hinted at in The Three Doctors and only briefly glimpsed in The War Games. This story introduces the characters of Borusa and the Castellan, recurring roles in later Gallifreyan stories. This story also establishes Gallifreyan civilisation, including the first mention of the Time Lord Academy, the Prydonians, the titles of Chancellor/President, and other aspects of Time Lord culture and hierarchy.
 * The novels Last of the Gaderene and Legacy of the Daleks explain how the Master became how he appears. However, in terms of televised adventures, there is no indication whether or not the Master seen here is necessarily the same incarnation of the Master as last seen portrayed by Roger Delgado in Frontier in Space. The 2017 Doctor Who Magazine comic strip story COMIC: Doorway to Hell follows on from this by depicting the Delgado version of the Master regenerating.
 * Part three's cliffhanger of the Doctor being drowned quickly became infamous for its terrifying nature, which caught the attention of media watchdog Mary Whitehouse and led to her lambasting the show. Because of intense negative reactions from the public, Philip Hinchcliffe was replaced as producer the following season and the BBC wiped the offending cliffhanger from the master 625 line PAL colour videotape, one of only a small amount of post-1974 Doctor Who footage to be affected in such a way; however, off-air U-matic videotape recordings of the uncensored broadcast were still left intact, and it was from these that footage of the infamous cliffhanger was sourced when the scene was restored on home media releases.
 * Part of the disturbing nature of the drowning scene at the end of part three came from the fact that Tom Baker suffers from aquaphobia and thus was experiencing a real fear of drowning during filming. Baker was reportedly so worried of the cliffhanger scaring kids that he visited a random family to watch part three with them and hear their responses.
 * This serial introduces the fact that a Time Lord has a regeneration cycle of only twelve regenerations for thirteen lives. This becomes a major plot point for the character of The Master in particular in later serials as he has reached the end of his regeneration cycle by the events of The Deadly Assassin. Following his resurrection to fight in the Last Great Time War as depicted in the revived series, the Master has a new regeneration cycle as seen in Utopia and The Doctor Falls which feature the Master suffering injuries that require regeneration though only the regeneration in Utopia is seen on-screen. The Doctor himself also suffers from this limitation: though he claims to Clyde Langer in the serial Death of the Doctor from The Sarah Jane Adventures to have 507 regenerations, this is proven to be a lie in The Time of the Doctor where the Doctor receives a new cycle at the end of his final incarnation.
 * At one point, Spandrell has to read aloud a disturbing letter that the Doctor has written for him. In rehearsals, he used a note written in English and thus had not bothered to learn the lines. When it came time to shoot the scene, David Maloney and the set designer switched it for a note written in Gallifreyan without telling George Pravda. The second Spandrell opens the note, he goes visibly pale and sweat springs from his forehead, and stumbles over his words as he struggles to remember them— the appropriate shocked reaction.
 * There is a scene where the Doctor is sitting on a chair trying to manipulate Spandrell, who begins explaining why he can't help the Doctor; and the Doctor shoots up from his chair mid-line and looms over Spandrell to intimidate him with his size — he audibly falters and his voice shakes. This was an ad-lib from Tom Baker, and George Pravda was just reacting with surprise to Baker unexpectedly going off-script.
 * At one point, it was planned to include a humorous title card at the end of part four reading, “We thank the High Court of Time Lords and the Keeper of the Records, Gallifrey, for their help and co-operation”. Ultimately, however, this was removed for fear that it lampooned the production too much.
 * David Maloney worked closely with designer Roger Murray-Leach and costume designer James Acheson to give Gallifrey a consistent, cohesive look. Although he would eventually be replaced on the serial by Joan Ellacott, Acheson contributed the Time Lords' distinctive high-collared apparel, while Murray-Leach reused a symbol he had designed for Revenge of the Cybermen as the Prydonian seal. Both would become enduring elements of Gallifrey's portrayal in Doctor Who, with the latter subsequently coming to be known as the “Seal of Rassilon”.
 * Robert Holmes disliked the previous portrayal of the Time Lords as omnipotent god-like beings, so he re-invented them as corrupt beureaucrats. He questioned why such a perfect society could produce so many criminals and renegades.
 * Robert Holmes and Philip Hinchcliffe reintroduced the Master in a transitional state so that their successors wouldn't be saddled with a version of the character they might find unsuitable.
 * The shot of Goth trying to drown the Doctor was filmed at the swimming pool of the Royal Alexandra and Albert School in Merstham, Surrey, because the pond water was too dirty.
 * Peter Pratt's uncomfortable mask was originally fitted with tubes which were intended to give the impression of fluid circulating around the Master's atrophied skull. However, this element was discarded when it was discovered that the effect was not visible under the studio lights.
 * The original cliffhanger to part two was the Doctor being attacked by the samurai. The train sequence was added when the episode overran.
 * Part three originally included a scene where a spider crawls up the Doctor's arm. This was scrapped when Bill Slater, the Head of Serials, thought it would be too scary for children.
 * Filming the scene where Goth tries to drown the Doctor was challenging for Tom Baker, who has a fear of water.
 * For a while, it was thought that episode four might introduce a new companion character. Robert Holmes had come up with the idea of the Doctor being accompanied by a Dickensian street urchin, whom he would mentor in the manner of Henry Higgins and Eliza Doolittle. As such, Holmes considered setting the climactic encounter between the Doctor and the Master in Victorian London. However, the new companion's introduction was eventually postponed until later in the season.
 * The scene where the Doctor is attacked by a biplane was supposed to be filmed at the Redhill Aerodrome in Redhill, Surrey.

Influences

 * The Manchurian Candidate
 * North by Northwest (the plane sequence)
 * Seven Samurai (a samurai appears in the Matrix)

Ratings

 * Part one - 11.8 million viewers
 * Part two - 12.1 million viewers
 * Part three - 13.0 million viewers
 * Part four - 11.8 million viewers

Myths

 * This is the only story to reference the fact that Time Lords get twelve regenerations for a total of thirteen lives, and the remainder of the classic series is consistent with the Second Doctor's implication in The War Games that Time Lords can regenerate an unlimited number of times unless their body is too badly damaged. Early interviews with the production team behind the 2005 revival (including David Tennant in Doctor Who Magazine #415) had made it appear as if the allocation of thirteen lives in this story is a piece of minutia unique to this story. In fact, the thirteen life limit has been a major plot element of at least four other stories, all of which involve villains attempting to steal the Doctor's remaining regenerations: The Keeper of Traken, Mawdryn Undead, The Ultimate Foe, and the 1996 TV movie. All of these stories referenced the thirteenth life limit in dialogue. Other Time Lords have been encountered since The Deadly Assassin in later stories who have reached their thirteenth and final incarnation, namely Azmael and Salyavin.
 * In The Time of the Doctor, the Eleventh Doctor acknowledged this limit as well and revealed that he was actually in his final incarnation, due to the Tenth Doctor using two and not counting his war incarnation. He was able to regenerate again at the end of this story only due to being granted a new cycle of regenerations by the Time Lords. The ability of the Time Lords to do this was revealed in TV: The Five Doctors, when it is offered to the Master; in TV: The Sound of Drums, it is confirmed that a new cycle was bestowed upon the Master during the Last Great Time War which has allowed the Master to regenerate at least four times since he was granted the cycle. (TV: Utopia, The Doctor Falls, COMIC: The Then and the Now, Fast Asleep)

Filming locations

 * Betchworth Quarry, Pebblehill Road, Betchworth, Surrey
 * Wycombe Air Park, Clay Lane, High Wycombe, Buckinghamshire
 * Royal Alexander and Albert School, Rocky Lane, Merstham, Surrey
 * BBC Television Centre (TC3 and TC8), Shepherd's Bush, London

Production errors

 * The guard the Master kills in part one begins to fall before the sound effect for the staser is heard. He is also seen again alive and well again in part two.
 * The corpse of the technician is clearly seen to be a Palitoy Action Man figure.
 * Near the end of part four, when the Master chases the Doctor up the Panopticon stairway, the Sash of Rassilon is over his shoulder. Before he puts it back down his front you can clearly see the brown cardboard backing.
 * After Hilred unlocks one of the TARDIS doors, the second guard to go through bumps into the other door.

Continuity

 * The story begins with the Fourth Doctor returning to Gallifrey due to a summons he received; this matches the end of TV:.
 * Reviewing the Doctor's history, the Time Lords find records of his exile to Earth by the Malfeasance Tribunal, as occurred in TV:, and also of his sentence eventually being lifted, as occurred in TV: . The latter decision is revealed to have been taken at the intercession of the Celestial Intervention Agency. Chancellor Goth is played by Bernard Horsfall, who also played the leader of the Tribunal in The War Games; although there is no evidence in-dialogue within The Deadly Assassin itself that he is playing the same character (and indeed, other sources suggested otherwise), PROSE: and PROSE:  would later suggest that Goth was indeed the First Time Lord from the trial.
 * The Decayed Master returns to using the Tissue Compression Eliminator, once used by the "UNIT era" Master in TV:, and the Doctor recognises the weapon's effects. Tissue compression would become one of the Master's default M.O.s in his next incarnation.
 * This story introduces the Eye of Harmony, the singularity from the heart of a black hole which an ancient Gallifreyan founder brought back to Gallifrey. Its narrative of events echoes, but does not quite match, the history of Omega's experiments as given in TV:, and gives Rassilon as the name of the Founder. Later sources would solidify the idea that Omega and Rassilon were contemporaries who worked together on the experiment. The creation of the Eye and disappearance of Omega would be depicted or referenced in many later stories including COMIC: , PROSE: , COMIC: and PROSE:.
 * The Doctor recalls that Time Lords are telepathic; Susan Foreman was depicted with psychic abilities as early as TV: and TV:, and the idea had also recently been referenced in TV: , where the Doctor instinctively recognises Morbius's mental presence even before they physically meet.
 * This story introduces the idea that Time Lords have finite regeneration cycles adding up to only twelve regenerations. Acquiring more regenerations would remain a key part of the Master's motivation in eras to come, starting with his next televised appearance in TV: and as late as TV: . The regeneration limit would also become a major plot point for the Doctor themself in TV:.
 * A great number of stories went on to address the circumstances which reduced the Master to his decayed form, including PROSE: and AUDIO:, both of which also attempt to address how and why Goth found him on the planet Tersurus.
 * The planet Tersurus, only mentioned here, would also serve as the setting of the notorious comedic special TV: .
 * The Master escapes Gallifrey in a TARDIS disguised as a grandfather clock; he is still using it when he next appears on television in TV:, in addition to another, more advanced TARDIS. AUDIO: would later clarify that this clock-TARDIS was Goth's own TARDIS, easily stolen by the Master with Goth now dead.
 * Goth's brother Rath appears in PROSE:.
 * Coordinator Engin reappeared in PROSE:, PROSE: , COMIC: and WC:.
 * Borusa reappeared a number of times, starting with TV:, being revealed to have taken on the Presidency after the Doctor ran off.
 * One of the entries in the Masterplan Journal given in PROSE: was set in the lead-up to this story, while the Master and Goth were formulating their evil plan.

DVD releases

 * The DVD was released on 11 May 2009 in the UK.

Special Features include:
 * Commentary by Tom Baker, Bernard Horsfall and Philip Hinchcliffe
 * The Matrix Revisited — Cast, crew and critics look back at the making of this story, featuring director David Maloney, designer Roger Murray-Leach and the founder of the National Viewers and Listeners Association, Mary Whitehouse
 * The Gallifreyan Candidate — A look at Richard Condon's novel The Manchurian Candidate, a major influence on the plot of The Deadly Assassin
 * The Frighten Factor — What exactly is Doctor Who's "Frighten Factor"? A diverse panel of experts try to answer the question.
 * Radio Times Billings — Listings for this story presented in a PDF file [DVD-ROM – PC/Mac]
 * Photo Gallery
 * Coming Soon Trailer
 * Production Information Subtitles
 * Easter Egg - Original BBC teaser for the serial. To access this hidden feature, press left at 'Photo Gallery' on the Special Features menu.


 * Editing for the DVD release was completed by the Doctor Who Restoration Team.


 * It was released as issue 52 of The Deadly Assassin.

Blu-ray releases

 * It was included as part of the Time Lord Victorious: Road to the Dark Times Blu-ray on 9 November 2020.

VHS releases

 * It was released in episodic format in the UK in October 1991. It was also re-released and digitally remastered for the W H Smith exclusive The Time Lord Collection in 2002, with a better quality freeze frame cliffhanger for part three.
 * This story was released in the US in March 1989 in edited omnibus format, two years before the UK release in episodic format. The US release was issued in a printed cardboard slipcase — bearing a flash reading Celebrating 25 Years of Doctor Who — as opposed to a plastic video case.

Digital releases

 * The story is available for streaming in Canada and the US through BritBox or Amazon Instant Video in the UK.
 * It is available on the Best of Tom Baker bundle on iTunes, alongside Genesis of the Daleks, The Hand of Fear and The Talons of Weng-Chiang.