Frontier in Space (TV story)

Frontier in Space was the third serial of season 10 of Doctor Who. It saw the introduction of the Draconians and the reappearance of. It was loosely connected with the following serial, Planet of the Daleks, and is significant for showing an alliance between the Master and the Daleks. The serial set the stage for the storyline that was later expanded into the Second Dalek War.

It is further notable as the final appearance of Roger Delgado in Doctor Who before his death. Delgado died in a car accident in Turkey in June of 1973, when his chauffeur-driven vehicle ran off the road and fell into a ravine, during the on-location shoot for the film Bell of Tibet. His character was meant to have a final encounter with the Doctor in the serial The Final Game, which was scrapped. Frontier in Space was the Master's last appearance until Robert Holmes and Philip Hinchcliffe brought the Master back as the main villain of The Deadly Assassin, albeit in a decaying form played by Peter Pratt.

The story also saw the first use of a refitted version of the sonic screwdriver model which debuted in Colony in Space. Instead of a silver emitter ring head, it now sported a red emitter ring head, with the addition of two semi-circular black magnets attached to the end, and the extending section of the screwdriver which once contained a red band and a set of alternating yellow and black coiling stripes was now unpainted in a plainly metallic colour scheme. This model of the sonic screwdriver remained in use by the Doctor all the way up to his fifth incarnation midway through season 19, where it was written out of the series in The Visitation.

Synopsis
The Third Doctor and Jo are caught in the escalating tension between planets Earth and Draconia and discover that and the Daleks are secretly working to provoke the two into all-out war.

Episode one
As the Earth cargo ship C982 moves through hyperspace, it narrowly avoids a collision with the TARDIS, which dematerialises out of the way and rematerialises in the ship's hold. The Third Doctor determines that they are in the 26th century. Jo sees a ship come alongside and hears a strange, high-pitched buzz. The ship shimmers, turning into a Draconian Galaxy-class battlecruiser. The two pilots, Stewart and Hardy, send out a distress signal and prepare for battle. When Hardy goes to get weapons, he meets the Doctor, but, thanks to the sound emitted by the enemy ship, he sees the Doctor and Jo as Draconians whilst Jo sees Hardy as a Drashig. Hardy escorts them at gunpoint as the Draconian captain orders C982 to surrender its cargo or be destroyed.

On Earth, the President and the Draconian ambassador (who is also the Emperor's son) accuse each other of attacking their ships and violating the frontier between the two empires established by treaty. General Williams reports to the President that a mission to rescue C982 is being prepared. Williams's hostility to the Draconians is well known — it was his actions that started the last war between the two — and the Prince believes Williams wants war again, a war, the Prince warns the President, that will see Earth destroyed. News of the attack spreads and anti-Draconian riots break out on Earth. The opposition calls for the government to take action. Locked up in C982's hold, the Doctor deduces that the strange sound was some kind of sonic hypnosis device that caused Hardy and Jo to see what they most feared. As the boarding party burns through the airlocks, Hardy gets the Doctor and Jo to use as hostages, but when the airlock door bursts open, the boarders are not Draconians, but Ogrons. The Ogrons stun the two pilots and the Doctor. They tie up Jo and take the ship's cargo and the TARDIS as they leave. When the Doctor revives and releases Jo, she tells him what the Ogrons did and wonders if they are working for the Daleks, as they were when she first met them. The Doctor points out that the Ogrons are mercenaries, and work for whoever employs them. When the rescue party arrives, Hardy and Stewart have stopped hallucinating, but with their memories garbled, they accuse the Doctor and Jo of being Draconian traitors...

Episode two
The two travellers get locked up again as C982 heads back to Earth. General Williams believes the Doctor and Jo are human agents planted by the Draconians to sabotage any war effort by Earth. He brings the two travellers to confront the Draconian Prince, but the Doctor denies working for the Draconians nor does the Prince recognise them. The Doctor tries to convince the President that a third party is trying to provoke the two empires into war. However, as the Doctor can provide no reason why someone would want to or any evidence to support his claim, Williams orders him and Jo be taken away and vows he will get the truth out of them.

In the Draconian embassy, the Prince arranges to help Jo and the Doctor "escape" so that they can be questioned. When the two are escorted from their cell to be brought to the President, a Draconian squad attacks, taking the Doctor prisoner. Jo tries to get more guards to help, but she is arrested instead. The Draconians question the Doctor, believing that he is involved in a plot with Williams to provoke a new war. The Doctor escapes but is recaptured in the compound by Earth troops. Once he is back in the cell with Jo, she hears the same sound as on C982. Outside, the Ogrons raid the prison, looking like Draconians thanks to the hypnosound. They break into the Doctor's cell and order him to go with them.

Episode three
The second escape goes no better than the first: the Doctor is recaptured again, and the Ogrons disappear. This second "rescue attempt" cements Williams' suspicions. He demands the president grant him the authority to strike first against the Draconians. The president agrees to break off diplomatic relations but will go no further without conclusive proof.

Williams puts the Doctor under a mind probe. It indicates the Doctor is telling the truth, which he is calmly repeating over and over. Williams refuses to believe it and orders increased power, but the probe overloads. The president orders the Doctor sent to the Lunar Penal Colony, where political prisoners are exiled for life, while Jo remains on Earth. Williams and the president receive records from the Dominion government of Sirius IV, a colony planet with some autonomy. The records "prove" the Doctor and Jo are citizens of Sirius IV and career criminals. A commissioner from the Dominion has arrived to claim jurisdiction — the Master.

On the Moon, the Doctor meets Professor Dale of the Peace Party, who shows him around. The Doctor tries to gain Dale's trust and includes him in his plans for escape. On Earth, Jo recognises the Master immediately and realises he was behind the Ogron attacks. The Master discovered the Doctor and Jo's presence when the Ogrons brought him the TARDIS. Given the unsavoury choice of going with the Master or staying in her cell, Jo agrees to go with him to fetch the Doctor.

Dale believes the Doctor. The peace with the Draconians lasted many years but suddenly devolved into senseless acts of hostility. The Doctor's fantastic story explains everything. Dale outlines the escape plan: Cross, one of the overseers, will leave two spacesuits near an airlock. They will cross the lunar surface and steal a spaceship. Dale offers to take the Doctor back to Earth where he can tell his story to Dale's contacts in the press and government. However, once inside the airlock, they find that the suits' oxygen tanks are empty. The Doctor tries to open the door, but it is locked. He and Dale realise Cross has tricked them and is pumping out the room's air...

Episode four
At the last moment, the Master arrives and restores the room's atmosphere. He obtains custody of the Doctor and gets him to come along quietly by revealing that he has Jo. Reunited with Jo in a cell in the Master's ship, the Doctor wonders why he is still alive. The Master explains that his employers are very interested in the Doctor. The Master sets the ship's automatic controls for the Ogron homeworld.

Pretending to tell Jo stories of his life, the Doctor uses a hidden steel wire to file through the cell's hinges. Jo blocks the security camera and natters, pretending to continue the conversation, while the Doctor sneaks out. Donning a spacesuit, he makes his way across the hull and into the flight deck. The Master puts Jo in an airlock, threatening to eject her into space if the Doctor does not surrender. The Doctor takes him by surprise. As the two face off, they do not see a Draconian battlecruiser approaching. Draconians enter the airlock where Jo is located.

The Draconian captain tells them all diplomatic relations with Earth have been severed. Violating Draconian space is punishable by death. The Doctor says he has vital proof for the Emperor and asks to speak to him. The captain locks up all three of them to take back to Draconia. However, the Master secretly activates a device whose signal is picked up by the Ogrons, who follow them to Draconia.

Episode five
As the ship arrives on Draconia, the Prince is speaking with his father, the Emperor, asking for permission to strike first at Earth. The Emperor, like the President, is hesitant. He knows such a war could bring down both empires.

The Doctor, Jo and the Master are presented to the Emperor, and the Doctor gives the ritual greeting, "My life at your command." The Prince is incensed that the Doctor has the temerity to address the emperor like a Draconian noble, but the Doctor says that he is a noble of Draconia — the title was given him by the 15th emperor, five centuries before, when he aided Draconia against a space plague. The Doctor accuses the Master of trying to start a war between Earth and Draconia using Ogrons and the hypnosound device. As the Emperor considers this, a courtier announces that an Earth spaceship has arrived. Jo hears the sound of the sonic device and realises it is the Ogrons. They burst in, guns blazing, and retreat with the Master, leaving several dead Draconians in their wake. One Ogron has been knocked out by the Doctor. As the effects of the hypnosound fade, the Emperor sees the "Earthman" before him transform into its true form and realises the Doctor is speaking the truth.

The Emperor decides the Ogron must be shown to the Earth authorities, but a Draconian ship would be shot down. The Prince, the Doctor and Jo will take the Master's police ship. As they cross the frontier into Earth space, they spot a ship following them. By the time they identify it as the Ogron ship, it has already launched its missiles. As the Doctor takes evasive action, the captive Ogron breaks out of its cell, overpowering its Draconian guard. It enters the flight deck and in the struggle cuts the ship's speed. The Prince and the Doctor subdue the Ogron, but the Master's ship catches up and a party boards the ship. A firefight breaks out on the flight deck, just as an Earth battlecruiser shows up. The Master recalls the boarding party, who rescue the Ogron prisoner and take Jo captive. Their ship zips away. The Earth battlecruiser places the Doctor's ship under arrest.

Without the Ogron, the president is unconvinced. The Doctor suggests a trip to the Ogron homeworld, but Williams thinks it a Draconian trick to divide Earth's forces. The Prince expects this response from Williams — after all, he started the first war. Williams lies and objects, but the Prince reveals what is in the Draconian court records. Twenty years before, the Draconians sent a battlecruiser on a diplomatic mission. When the Draconian ship did not answer hails, Williams gave the order to attack. The battlecruiser was unarmed, its missile banks empty, and the reason it did not answer was because its communications systems were destroyed in the same neutron storm that had damaged Williams's ship. Williams is shaken by the prince's revelation and apologises for the wrong he had done to the Draconians. Williams now intends to lead the expedition to the Ogron planet himself.

The Master brings Jo to a bunker on the Ogron homeworld, where he shows her the TARDIS. He plans to use Jo and it as bait for the Doctor. He tries to hypnotise Jo, first with his own powers and then with the hypnosound.

Episode six
Jo's mind is strong enough to resist. The Master orders her taken away. An Ogron reports that one of their ships found and attacked two Earth cargo ships, destroying one. The Master is delighted. This means that war is not far off, and, indeed, cries for war from Earth are at a fever pitch.

Williams prepares his personal scout ship. The Doctor and the Prince accompany him as it heads at top speed to the coordinates the Doctor got from the Master's ship. Using the spoon brought with a bowl of thick broth, Jo digs her way into the next unlocked cell and sneaks further into the bunker as Williams's ship enters orbit, and they avert near destruction from a Draconian cruiser. She pockets the hypnosound, then finds a pad with the coordinates of the planet and the bunker. She transmits a distress signal with the information. The Master shows up, revealing that he deliberately left the coordinates for Jo to find, the signal was muted, and only the Doctor could read it. His ship has been detected in orbit. When he comes, the trap will be sprung.

Williams' party lands nearby, not knowing the Ogrons have set up an ambush. The Ogrons open fire on them but are frightened away by an orange, slug-like lizard they call the Eater. The Master is furious, and warns them their masters are coming. This terrifies them more than the monster. Williams' group hears the roar of a landing spaceship. When they look at the ridge, they see the Master, accompanied by several Daleks, who exterminate Williams' men before they can fire. The Daleks want to exterminate the Doctor immediately, but the Master proposes that the Doctor be placed in his hands, to be allowed to see the galaxy and Earth in ruins before they kill him. The Gold Dalek agrees and leaves for its ship to prepare the Dalek army on another planet.

The Doctor explains the Daleks were behind the war so they could deceive the empires to destroy each other, thus weakening the universe for conquest. The Doctor modifies the stolen hypnosound, making the Ogron guard see him as the Gold Dalek; in fear, the guard unlocks the cell gate and runs away. The Doctor tells Williams and the Prince to get the word to their respective governments and mount a joint expedition against the base on the Ogron planet. The Doctor and Jo find their way to the TARDIS but are surrounded by the Ogrons and the Master, who trains a blaster on the Doctor. The Doctor activates the hypnosound, panicking the Ogrons. One accidentally knocks the Master's arm, making him fire, the shot grazing the Doctor's head. The Master and the Ogrons scatter, giving Williams and the Prince the chance they need to escape and warn Earth and Draconia. The Doctor, barely conscious, has Jo help him into the TARDIS. He staggers to the console, dematerialises the ship, then presses his palms to the telepathic circuits, sending a message to the Time Lords. The TARDIS spins away into space...

Cast

 * Dr. Who - Jon Pertwee
 * Jo Grant - Katy Manning
 * - Roger Delgado
 * President of Earth - Vera Fusek
 * General Williams - Michael Hawkins
 * Draconian Prince - Peter Birrel
 * Draconian First Secretary - Lawrence Davidson
 * Cell guard - Timothy Craven
 * Gardiner - Ray Lonnen
 * Kemp - Barry Ashton
 * Hardy - John Rees
 * Stewart - James Culliford
 * Newscaster - Louis Mahoney
 * Draconian space pilot - Roy Pattison
 * Secretary - Karol Hagar
 * Professor Dale - Harold Goldblatt
 * Patel - Madhav Sharma
 * Prison Governor - Dennis Bowen
 * Cross - Richard Shaw
 * Sheila - Luan Peters
 * Technician - Caroline Hunt
 * Lunar guard - Lawrence Harrington
 * Draconian captain - Bill Wilde
 * Draconian Emperor - John Woodnutt
 * Draconian messenger - Ian Frost
 * Earth cruiser captain - Clifford Elkin
 * First Ogron - Stephen Thorne
 * Second Ogron - Michael Kilgarriff
 * Third Ogron - Rick Lester
 * Congressman Brook - Ramsay Williams
 * Newscaster - Bill Mitchell
 * Pilot of space ship - Stanley Price
 * Daleks - John Scott Martin, Cy Town, Murphy Grumbar
 * Dalek Voice - Michael Wisher

Crew

 * Assistant Floor Manager - John Bradburn
 * Costumes - Barbara Kidd
 * Designer - Cynthia Kljuco
 * Film Cameraman - John Tiley
 * Film Editor - John Bush
 * Incidental Music - Dudley Simpson
 * Make-Up - Sandra Shepherd
 * Producer - Barry Letts
 * Production Assistant - Nicholas John
 * Script Editor - Terrance Dicks
 * Special Sounds - Dick Mills
 * Studio Lighting - Ralph Walton
 * Studio Sound - Brian Hiles
 * Theme Arrangement - Delia Derbyshire
 * Title Music - Ron Grainer
 * Visual Effects - Bernard Wilkie, Rhys Jones

Uncredited crew

 * Technical Managers - Tommy Dawson, Ron Bristow (INFO: Frontier in Space)
 * Vision Mixers - Mike Turner, Shirley Coward (INFO: Frontier in Space)
 * Floor Assistant - Christopher Moss (INFO: Frontier in Space)
 * Production Secretary - Sarah Newman (INFO: Frontier in Space)
 * Props Buyer - Ruth Hyde (INFO: Frontier in Space)
 * Music Copyist - George Bayton (INFO: Frontier in Space)
 * Grams - Gordon Phillipson (INFO: Frontier in Space)
 * Post-Production Sound - Ray Angel (INFO: Frontier in Space)

The Doctor

 * The Doctor once served as a delegate at the Third Intergalactic Peace Conference.
 * The Medusoids used a mind probe on him; he claimed he was on his way to meet a giant rabbit, a pink elephant and a purple horse with yellow spots.

Literature

 * In a moment of leisure, the Master relaxes with a copy of H. G. Wells's novel The War of the Worlds.

Species

 * Jo sees Drashigs, a Sea Devil, and a Mutt due to the Master's fear machine.

United Nations Intelligence Taskforce

 * While distracting the Master so the Doctor can get to the outside of the ship, Jo mentions that people thought of her job at UNIT as hanging out with James Bond-type characters and going to fancy dinner parties while she claims in reality it's just doing filing for the Brigadier or else running around making tea and being a general "dogsbody".

Foods and beverages

 * Cross confiscates chocolate from Patel.
 * The President and General Williams drink wine.
 * Jo gives the Ogron prisoner a banana.

Story notes

 * This story had the working title Frontiers in Space.
 * The original outline had the Cybermen working with the Master, but they were swapped for the Ogrons before scripting started.
 * The conclusion of this story ends on a cliffhanger leading straight into Planet of the Daleks. Originally both this story and Planet of the Daleks were going to be a 12-part story, and as the two storylines are connected, they are often unofficially considered as such.
 * An unfortunate error was made at the time of production, whereby one of the on-screen cast credit slides for episode one was inadvertently substituted for one of those from episode two. This resulted in Lawrence Davidson (Draconian First Secretary) and Timothy Craven (Cell Guard) not being credited on-screen for episode two, though they were credited in Radio Times, and Louis Mahoney (Newscaster) and Roy Pattison (Draconian Space Pilot) being repeated — even though their characters appeared only in episode one.
 * Assistant floor manager John Bradburn plays the Ogron eater monster seen on the Ogrons' planet.
 * During editing, the first scene of episode three, following the reprise, was drastically cut down for timing reasons: a key background scene was eliminated and the character of Sheila, assistant to the President of Earth, was reduced to merely that of a walk-on who massaged the President whilst she talked to her secretary. In the complete version of the scene, Sheila had discussed the origins of the tensions between Earth and Draconia with the President, during which it was revealed that the young General Williams had destroyed a Draconian battle-cruiser — not realising that it was unarmed, and merely being used to transport the Draconian envoy — in a blast from his own spacecraft's exhaust rockets. Luan Peters (Sheila) retained an on-screen credit despite no longer having any lines.
 * During the scene in the President of Earth's office in episode six, where the Doctor, the President and the Draconian prince watch on a large wall-mounted video screen a news film report of Congressman Brook at a political rally calling for war with Draconia, Bill Mitchell was originally to have featured as a newscaster, announcing the news of the rally and introducing the film report. Unfortunately, either due to the episode overrunning or a decision by Paul Bernard to use only the footage of Congressman Brook, Mitchell's appearance was edited out of the finished programme. This decision appears to have been made at a late stage, which explains why Mitchell is still credited both on-screen and in Radio Times.
 * John Scott Martin is credited as "Chief Dalek" in Radio Times, while Cy Town and Murphy Grumbar are credited on-screen but not in Radio Times.
 * Episode six had to be revised after it was delivered by director Paul Bernard. Barry Letts greatly disliked the way the Ogron eater had been realised by the production team and tried to limit its inclusion in the serial. Unfortunately, it was centre stage in the final moments of episode six, and the only way to get rid of it was to film a corrective pick-up on the first day of studio recording for Planet of the Daleks. This meant that, technically, episode six contained some work by Planet of the Daleks director David Maloney. However, this did not alter Bernard's sole directing credit for the episode.
 * Episode five is one of only two episodes in Doctor Who history to feature the "Delaware Theme" during its opening as well as its closing credits. The UK broadcast used the standard theme music, but the version sent to Australia already had the unused arrangement edited in.
 * When the Doctor uses the stolen hypnosound to appear as a Dalek to the Ogron guard in episode six, his commands are provided by Dalek voice actor Michael Wisher.
 * Reviewers have observed that the precipitating incident of the first Earth-Draconia war, as depicted in this story, is very similar to the beginning of the Earth-Minbari War in the 1990s television series Babylon 5. Both space wars begin because an Earth vessel misinterprets the approach of an alien ship as a threat and fires on the ship based on this misunderstanding.
 * 8A Fitzroy Park at Highgate, London, which was used as the exterior of the Draconian embassy, was at the time the home of another BBC director, Naomi Capon.
 * After remaining unnamed for several decades, the President of Earth was finally given the name Dora in the audio story The Transcendence of Ephros.
 * Jon Pertwee named the Draconians as his favourite monster, largely because of how expressive they were and thus easier to act alongside than Daleks. He was fond of recounting how he had a conversation about space travel, the stars and the planets with one of the Draconian actors during a night shoot without noticing the actor was in costume.
 * At Terrance Dicks' suggestion, the President of Earth became female, with Malcolm Hulke taking care to note that she was not the first woman to hold the office.
 * The same three Dalek casings used for Day of the Daleks appeared in episode six.
 * The Doctor's discovery that the attacks in space were being committed by Ogrons initially came much later, after the Master had liberated him from prison.
 * The notion of the hypnosound was developed to replace the physical masks the Ogrons wore in the original storyline.
 * At the lunar penal colony, Patel was originally called Doughty — a name reused by Malcolm Hulke for the novelisation.
 * Harold Goldblatt had previously appeared with Jon Pertwee in a 1938 radio production in Belfast entitled Lillibullero, which was one of Pertwee's earliest radio performances.
 * The serial made use of spaceship props acquired from Gerry Anderson's Century 21.
 * The Draconian Empire was originally named the Andromedean Empire.
 * Malcolm Hulke originally intended the Draconians to be like the post-Napoleonic Hapsburgs.
 * The Doctor's discovery that the attacks in space were being committed by Ogrons initially came much later, after the Master had liberated him from prison.
 * The notion of the hypnosound was developed to replace the physical masks the Ogrons wore in the original script.
 * Patel was originally named Doughty.

Ratings

 * Episode one - 9.1 million viewers
 * Episode two - 7.8 million viewers
 * Episode three - 7.5 million viewers
 * Episode four - 7.1 million viewers
 * Episode five - 7.7 million viewers
 * Episode six - 8.9 million viewers

Myths

 * The fifth episode as seen on the BBC Video release of this story, which is about a minute longer than the one originally transmitted and features the abandoned Delaware synthesiser arrangement of the theme music, is a special "extended version". (It is a rough cut that was prepared during the original editing of the story and never intended for public consumption.)
 * Roger Delgado died soon after appearing in the episode, which is why the Master doesn't appear in Planet of the Daleks. (He died several months later; there's no indication the Master was ever intended to appear in the second chapter.)
 * A related rumour states that Katy Manning decided to leave the series after Delgado's death. (In fact, by the time Delgado died (June 1973), Manning's final episode had already been filmed (April 1973), and her decision to leave would have likely been made by the time Frontier in Space had been shot, even if the rumour above was true.)

Filming locations

 * Hayward Gallery, Belvedere Road, Lambeth, London
 * 8A Fitzroy Park, Highgate, London
 * Beachfields Quarry, Cormongers Lane, Redhill, Surrey
 * South Bank Centre, Waterloo, London
 * Bray Studios, Slough
 * Ealing Studios, Ealing Green, Ealing
 * BBC Television Centre (Studio 3 & 4), Shepherd's Bush, London

Production errors

 * Jo splits her trousers while running to escape the Ogrons in episode three.
 * Jo's tights change colour from scene to scene (and occasionally she isn't wearing any at all).
 * Big strings can be seen holding up the Doctor when he exits the Master's stolen prison transport ship in episode four, and again for his second spacewalk in episode six.
 * As the space walking Doctor opens the airlock in episode four, there is a technician visible inside it. Their hand is caught in the shot and can be seen helping the hatch open below for a brief moment before being pulled back out of view.
 * During the Doctor's spacewalk, the wires on the Doctor are clearly visible while he is climbing the outer hull of the ship.
 * During episode two when the Doctor rolls back on his chair to escape his Draconian captors, it is quite obvious that he isn't Jon Pertwee, but a stunt double in a wig.
 * When Jo helps the Doctor to his feet on the Ogron Planet, she is holding the Master's gun, but when she is helping him inside the TARDIS, the gun disappears.

Continuity

 * Jo refers to Solos and the Earth Empire. (TV: The Mutants)
 * The Doctor tells Jo the story of his trial. (TV: The War Games)
 * PROSE: Legacy of the Daleks and COMIC: Doorway to Hell are both set (for the Master) after this story.
 * PROSE: Love and War is set after this story, when Earth and Draconia are at relative peace.
 * The Tenth Doctor would later (accidentally) travel back to the war in PROSE: Prisoner of the Daleks and help put an end to the Dalek threat.
 * This story is referenced by the Eleventh Doctor in PROSE: Apollo 23. He describes his imprisonment on the Moon as "cool". He revisits what will become the prison, but it only has a few prisoners and is a moonbase.
 * Jo would later remember the events of this story along with others in TV: Death of the Doctor.
 * would later mention their encounter with the Daleks to the Tenth Doctor. As the Master lay dying and refusing to regenerate shortly afterwards, the Doctor asked him to remember all of their experiences, including their encounter with the Daleks. (TV: Last of the Time Lords)
 * The Master was sent on his mission by the Dalek Emperor. (AUDIO: The Dalek Conquests)
 * The Lunar Penal Colony was operational by 2144. (AUDIO: Repeat Offender)
 * In Planet of the Ogrons, it is revealed that, originally, there weren't any Ogrons in this adventure, but, in the Time War, the Daleks started to tamper with Ogron history at the point in which they were included in this event.
 * The Master, shortly after rescuing the Doctor from the Lunar Penal Colony, recalls the time The Doctor visited him in prison. Additionally, after she is brought by the Master to his quarters on the Ogron Homeworld, Jo states that the Master was, "better off in prison." (TV: The Sea Devils)
 * Jo remarks that being hypntotised by the Master once was quite enough. (TV: ''Terror of the Autons)

DVD releases
This story was released in a box set called Dalek War, along with Planet of the Daleks. The DVD was released in the UK (Region 2) on 5 October 2009, in Australia and New Zealand (Region 4) on 4 February 2010, and in North America on 2 March 2010.

Special features

 * Commentary by Katy Manning (Jo Grant), Barry Letts (Producer) and Terrance Dicks (Script Editor), moderated by Clayton Hickman
 * Perfect Scenario: Lost Frontier — In the far future, Zed, a young scenariosmith, turns to the world of Doctor Who to help him connect to his audience. Including interviews with Vera Fusek (The President) and Michael Hawkins (General Williams)
 * The Space War — Cast and crew look back at the making of this story
 * Roger Delgado: The Master — A biography of actor Roger Delgado, featuring unseen photographs, rare excerpts from his TV appearances and interviews with those who knew and loved him
 * Stripped for Action — The Third Doctor — The series looking at the Doctor's comic book adventures reaches his third incarnation
 * PDF materials - Production design drawings, Radio Times listings and BBC Enterprises sales literature (DVD-ROM - PC/Mac)
 * Production Information Subtitles
 * Photo Gallery
 * Coming Soon Trailer - Kamelion Tales
 * Easter Egg: VT countdown for episode five and opening and closing credits with the unused "Delaware" arrangement of the Doctor Who theme. To access this hidden feature, press down at Special Features on Disc Two's Subtitles menu to illuminate the Doctor Who logo.

DVD errors

 * The DVD booklet of the Region 2 version, in the section describing the commentary, the images of Barry Letts & Terrance Dicks are mismatched to each other's biography.
 * In the scene selection for episode two, the image used for chapter 6 actually comes from episode three.

Digital releases
This story is available:
 * for streaming through BritBox (Canada and US) as part of Season 10 of Classic Doctor Who.

VHS releases

 * This story was released in August 1995. BBC Video 5640
 * Episode six was included on the VHS documentary The Pertwee Years