Frontios (TV story)

Frontios was the third serial of season 21 season of Doctor Who.

Eric Saward asked former script editor Christopher H. Bidmead to contribute a story and Nathan-Turner requested that it be monster-centric. This would be a significant change from Bidmead's earlier stories, Logopolis and Castrovalva, as neither had featured monsters.

It was originally intended that Tractator technology should incorporate human remains, but this was deemed too gruesome. This idea was taken up in the 2006 episode The Girl in the Fireplace.

The production of Frontios was blighted by two very sorrowful events. After completing much of the preparatory work for Frontios, designer Barrie Dobbins went on leave, and a year later, took his own life; his place was taken by David Buckingham. Following this, Peter Arne, who had been cast to play Range, was brutally murdered in his home.

As with Warriors of the Deep, a number of difficulties were experienced with the Tractator costumes. They were too constricting to allow for the curling manoeuvres described in the script, so this was cut. Although Bidmead was asked to submit another Tractator script, and he submitted two further scripts to Saward, Frontios was Bidmead's final contribution to Doctor Who.

The story was notable for the destruction of the TARDIS. This created the impression that the Doctor and his companions were stuck at the end of the universe.

Synopsis
"Frontios buries its own dead", or so the saying goes.

The Doctor, Turlough and Tegan are forced into landing on the remote planet of Frontios, a human colony where deaths go unaccounted for. Under constant threat from lethal meteorite bombardments, few of the doomed colony members realise that the ground of Frontios itself opens up and devours the unwary. Not permitted to assist, the Doctor's attempt to leave is thwarted when the unimaginable occurs: the TARDIS is destroyed.

All the while, burrowing undetected below the planet's crust, an alien force prepares a final and gruesome fate for all humanity...

Part one
Captain Revere, the leader of the human colony on Frontios, has led an expedition of Orderlies into the tunnels beneath the planet's surface to study the minerals there. As he does so, the ground itself begins to move beneath him, and the tunnels cave in when a support beam shifts in place. Revere is buried beneath the rubble, and Chief Orderly Brazen tries to rescue him — only to find, when the dust clears, that Revere's body has vanished. Unnerved, Brazen decides to cover up the true facts of Revere's death and claims that he was killed by an explosion in the research room and orders all witnesses to the incident to keep quiet. The research room is thus sealed off, much to the disgust of the colony's chief scientist and medical officer, Mr Range.

While the Doctor tries to work out where to position the TARDIS hatstand, his ship drifts far into the future and comes to rest around Frontios — one of the last outposts of human civilisation following the collision of the Earth with its sun. The Doctor refuses to put down, as these times mark the far limit of Gallifreyan knowledge; as the colony is still in its infancy any interference could prove disastrous. But before he can depart, the TARDIS is swept up in a meteor shower — and, much to his surprise, his ship is dragged down to Frontios by the planet's gravitational pull.

The meteorites bombard the colony, and the people scatter in panic as klaxons sound. The TARDIS materialises as the bombardment begins to die down, and the Doctor instantly rushes to the aid of an injured colonist. Turlough and Tegan help Norna, Range's daughter, to carry the injured to the medical shelter, where Range is surprised by the presence of the three strangers but accepts the Doctor's medical advice. The Doctor is taken aback by the primitive state of the medical facilities, lack of basic medical technology and the almost non-existent lighting. Despite the rules against interference the Doctor tells Tegan and Turlough to fetch the mu-field generator from the TARDIS so he can at least provide Range with decent lighting. But Tegan and Turlough find the inner door of the console room jammed in place as if twisted out of shape by some powerful force. Meanwhile, Brazen reports the strangers' arrival to Revere's son, Plantagenet, and both fear that this could herald the beginning of the invasion they've expected for so long.

The Doctor doesn't pay attention to Tegan and Turlough's story when they return; he's fully occupied by Range's explanation of how the colony ship crashed on Frontios. All of their technology failed and was destroyed in the crash, and after they spent a decade tilling the fields the bombardments began. Although there is little doubt that the colonists of Frontios are being deliberately attacked, nobody yet knows why, or by whom. Tegan and Turlough, meanwhile, discuss the lighting situation with Norna, who offers to help them break onto the colony ship and steal an acid jar from the research room, in order to run more power through the weak phosphor lamps.

As Brazen and Plantagenet emerge from the colony ship, Norna helps Tegan and Turlough to sneak on board — but they are spotted, and Brazen follows them with a squad of orderlies. They manage to evade the Orderlies and get into the research room, where they use a block and tackle to lift the heavy battery out onto the hull of the ship. Unfortunately, their escape route is blocked; an Orderly named Cockerill has stolen extra food from the ration stores, and he and his fellows have settled in for an illicit meal.

Norna decides to lower the acid battery over the side of the ship, but as they near the ground they are spotted by the warnsman, who normally keeps an eye out for signs of the bombardment. He rushes over to confront them and is accidentally knocked out by the swinging battery — as the skies begin to darken...

Plantagenet marches into the medical shelter to confront the Doctor and accuses him of spearheading the invasion for which the bombardments have been a softening-up process. Range protests that the Doctor has tried to help, but Plantagenet refuses to listen — particularly when Brazen arrives with word that Range's daughter has helped the other two "invaders" to break onto the colony ship. The Doctor warns that fear and paranoia will only drive the colony to extinction, and offers to show Plantagenet and Brazen the harmless interior of the TARDIS. But as they leave the medical shelter, Norna arrives with the unconscious warnsman — and the bombardment begins. The Doctor, Tegan and Turlough shelter under a wing of the colony ship as the colonists rush back to the medical shelter; Plantagenet seems out of breath when he arrives, but assures Brazen that he's all right. The Doctor and his companions wait out the bombardment and decide to leave the hostile colonists to their own devices. But as they approach the TARDIS, they find only the Doctor's hatstand, stuck in the middle of a smoking pile of rubble. The TARDIS has been destroyed...

Part two
The Doctor, still trying to come to terms with the loss of the TARDIS, is surrounded by an impromptu firing squad of orderlies. Norna stands in the line of fire, pointing out that even if the Doctor is an invader he will at least know why the colony is under attack. When the Doctor is unable to answer the question immediately, Plantagenet orders his men to open fire. Turlough grabs the nearest weapon, which happens to be the TARDIS hatstand — and a small explosion scatters rubble about the area. The Doctor identifies the effect as the result of residual energy from the TARDIS, but Plantagenet and Brazen are convinced that the hatstand is, in fact, a weapon — perhaps the very one which brings down the bombardment.

Turlough uses the hatstand to hold the orderlies at bay, while the Doctor offers his help to find answers. Revere spent his life trying to find precious minerals beneath Frontios, but the Doctor intends to analyse the meteorites instead and find out where they're from. Plantagenet and Brazen reluctantly accompany the Doctor back to the research room, held at bay by the hatstand — but once in the research room, Plantagenet tries to strike Turlough down with a crowbar. Turlough swings around with the hatstand and Plantagenet, although untouched, collapses, clutching his heart. The Doctor puts an end to the farce and checks out Plantagenet — who was struck a glancing blow during the bombardment and has been trying to carry on regardless. The Doctor accompanies Brazen and Plantagenet to the medical shelter while Turlough and Norna begin analysing the meteorite fragments.

Tegan, meanwhile, has been helping Range to set up the new lighting system with the acid battery, and in the process learns more about the disaster that is Frontios. Colonists regularly desert the failing colony to live retrograde lives out in the wilderness, and the orderlies have begun to shoot deserters — although each death increases the possibility of the colony's extinction. Tegan notices that Range is keeping a set of files about deaths, and while Range is distracted by an emergency Tegan studies the files and finds one marked "Deaths Unaccountable". Range catches her and orders her not to mention the file to anyone.

At that moment, the Doctor arrives with Brazen and Plantagenet and uses the acid battery jar as a defibrillator to save Plantagenet's life. Brazen still isn't sure of the Doctor's intentions but is more willing to trust him. Plantagenet is still weak, but refuses to leave the medical shelter for his quarters on the colony ship; he must stay in full view of the colonists, for if they believe he is dead anarchy will result.

Turlough wonders why the colonists don't dig underground shelters, but Norna claims that Revere outlawed digging beneath the earth. Turlough realises that some of Revere's rock samples are labelled with dates from after the quarry was supposedly closed, and eventually deduces that the block and tackle which they used earlier with the acid battery is in fact there to lift up the floor plates. Beneath the research room, he and Norna find secret tunnels in which Revere continued his subterranean exploration and analysis. The rock in the tunnels is strangely moth-eaten, and as they continue on they find an area in which the walls are polished as smooth as glass. Turlough finds it all unnervingly familiar, and realises that a word, or name, is appearing in his memory... but where has he heard the word "Tractators" before? He wants to go back, but Norna insists that they continue on — unaware that they are being followed by two creatures like giant woodlice...

The Doctor and Range return to the research room, leaving Tegan and Brazen in the medical shelter. Tegan is coming to understand Brazen's difficult position, but while talking with him she accidentally lets slip about the existence of Range's secret files. Brazen concludes that Range is the one spreading rumours and sedition, but as he calls the orderlies together to take action, Tegan hears Plantagenet crying out for help — and arrives just in time to see him sink down through the ground and disappear. At that moment Cockerill arrives with a group of colonists, and Brazen bluffs them away, claiming that Plantagenet has better things to do than appear for their benefit. Tegan, realising things are getting out of control, slips away back to the colony ship — only to find that the colonists are already looting it. The anarchy which Plantagenet had feared has begun.

The Doctor and Range find the open floor panel in the research room, and Range admits that he believes Revere closed the quarry after discovering something dangerous below ground. They enter the tunnels to search for Norna and Turlough, but it's Turlough who finds them — he's rushing back along the tunnels, screaming, and babbling about Tractators. As Turlough collapses into catatonia, the Doctor continues onwards, and Tegan arrives moments later and follows him. The Doctor finds Norna surrounded by a group of Tractators, who are exerting some sort of force to hold her immobilised. Tegan nearly stumbles into their midst, and the Doctor warns her back — but he is spotted, and the Tractators use the same force to drag him into their midst along with Norna...

Part three
Tegan throws her phosphor lamp to the ground, the burst of light and fire distracting the Tractators and breaking their grip on the Doctor and Norna. Tegan gets Norna to safety, while the Doctor keeps the Tractators occupied. She then returns for the Doctor and is captured by the same gravity beam which is holding him. Range arrives to see the Doctor and Tegan being dragged away by controlled gravitational forces, and the Doctor warns him to get Norna and Turlough to safety. As the Tractators approach, the Doctor throws his own phosphor lamp at them, breaking their hold on him. He and Tegan flee into the tunnels and manage to shake off the pursuing Tractators.

Brazen attempts to restore order in the colony, but even Cockerill has gone Retrograde, claiming that Frontios is finished. Brazen lets Cockerill out of the colony ship with his stolen food but doesn't lift a finger to help him when he is set upon by other Retrogrades and beaten nearly to death for his rations. Lying helpless on the ground, Cockerill is drawn down through the earth as the Retrogrades watch — but in the tunnels below ground, the Doctor and Tegan stumble across the Tractator responsible, and are forced to flee when it abandons its former quarry and turns its attention to them. When Cockerill rises from the earth, the Retrogrades are amazed — surely a man who can free himself of the hungry earth can do anything.

As Norna and Range carry Turlough back to the surface, he continues to babble about the Tractators and their invasion of his homeworld, as deep ancestral memories surface from his unconscious. He refers to them as an infection of the planet — and their intentions are evil. As they near the entrance to the colony ship, Norna finds a shred of map with Revere's handwriting on it — proof that he knew or suspected the presence of the Tractators. Upon arriving at the research room, however, Range and Norna are arrested by Brazen, who accuses Range of spreading disinformation to subvert law and order on Frontios.

Range has been collecting facts and statistics to prove that the legends of "the hungry earth" are true — and it now becomes clear that, while Revere kept his suspicions secret to avoid panic until he knew the true nature of the threat, Range was keeping the vital information secret because of his leaders' conspiracy of silence. Turlough slowly begins to recover from the shock of his ancestral memories surfacing, and when Brazen admits the true facts about Revere's death, Turlough informs him that Revere and Plantagenet may still be alive. The Tractators need living minds as well as bodies to carry out their plans. Brazen decides to lead the Orderlies into the tunnel system to rescue his colony's leaders, and Range offers to guide them while Norna remains with the still-recovering Turlough. Turlough, ashamed of what he now sees as his cowardice, eventually sets off after the expedition to help them — unaware that Retrogrades are on the loose in the colony ship, and that he's left Norna alone in their midst...

As the Doctor and Tegan search for a way out of the tunnels, they find clear evidence that the Tractators are technologically advanced, and are mining out the tunnel system and polishing its walls for some reason. The leader of the Tractators, the Gravis, is holding Plantagenet prisoner in the Tractators' main cavern, waiting for the old driver of the excavation machine to expire before it installs Plantagenet in his place. The Gravis decides to send out the excavation machine to bring the Doctor to it. In the tunnels, the Doctor and Tegan hear the machine approaching and are forced to retreat from it into the main cavern. There, they watch in horror as the machine enters the cavern — with the emaciated body of Captain Revere held in its clutches, his mind slaved to its controls...

Part four
The Gravis seems to know the Doctor by reputation and is intrigued when Tegan inadvertently reveals that they travelled to Frontios by TARDIS. As the Tractators have been marooned on Frontios for centuries, the Gravis is obsessed with means of travel. The Doctor seems to side with the Gravis, pointing out that the Tractators were here long before the humans arrived; Tegan is furious with him, but the Doctor informs the Gravis that she's a malfunctioning android and the Gravis has a Tractator pinion her in a side cave out of the way. Captain Revere has finally died, and the Gravis is now preparing to install Plantagenet in his place. The Doctor has by now worked out that the colony ship's crash was caused by the Tractators, who allowed the colonists a decade to establish themselves before beginning the bombardments, using their control over gravity to draw the system's asteroids down upon the planet. He has also concluded that the polished tunnel system is intended as a waveguide to amplify the power of the Tractators' gravity beams. What he doesn't yet know is why...

Turlough catches up with Brazen and the others, and Range returns to the colony ship to ensure that Norna is all right. The Orderlies reach the Tractators' caverns, where they rescue Tegan and rush into the main cave. The Doctor takes advantage of the distraction to release Plantagenet from the excavating machine, and when he breaks the link an electrical charge earths itself through the nearby Gravis, stunning it. The Tractators are unable to function independently without the Gravis, and in the confusion which follows the orderlies attempt to retreat. Turlough, however, is mesmerised by the excavation machine, which symbolises all that is evil about the Tractators in his unconscious memory. Brazen manages to pull Turlough away from the machine but is himself caught by its thrashing linkages. He orders the Doctor to get the others to safety as the machine runs out of control and begins to tear him apart.

Range is captured by a Tractator on his way back to the colony but escapes when it is thrown into confusion by the loss of the Gravis. Meanwhile, Norna is attacked by a Retrograde but is rescued by Cockerill — who is now the leader of an army of Retrogrades trying to take command of Frontios and restore order. They don't believe Norna's wild story about Tractators until Range arrives, terrified and shaken by his experiences, and convinced that Frontios is doomed.

The Doctor, Tegan, Turlough and Plantagenet shelter in the nearby tunnels, and Plantagenet reveals that he knows the Gravis' plan; the extended tunnel system is to act as a gravity motor, enabling the Tractators to pilot the entire planet throughout the galaxy and conquer other worlds. And Turlough has remembered the Tractators' greatest weakness; the Gravis is the source of all their power, and once separated from it they will become harmless burrowing insects. The Gravis recovers and they are forced to flee into the tunnels — and the Gravis, realising that Tegan is not an android after all, decides to use her as the new driver for the excavating machine.

Tegan wanders around in the tunnels and comes across bits of the TARDIS's inner walls. She is chased by the Gravis, who has now regained consciousness, and two of his Tractators. She inadvertently comes upon one of the TARDIS's inner doors and she opens it to find herself in the TARDIS console room, which has bits of rock wall mixed in with its normal walls. She also finds the Doctor, Turlough and Plantaganet hovering around the console. The Doctor ushers the Gravis in and then tricks him into reassembling the TARDIS by using his power over gravity. The Gravis pulls the TARDIS back into its normal dimension.

Once fully assembled, the Gravis is effectively cut off from his fellow Tractators, which revert to a harmless state. The Doctor and Tegan deposit the now-dormant Gravis on the uninhabited planet of Kolkokron. Returning to Frontios, the Doctor gives Plantagenet the hatstand as a farewell token and asks that his own involvement in the affair not be mentioned to anyone, especially the Time Lords. Once the TARDIS has left Frontios, its engines start making a worrisome noise. The Doctor appears to be helpless as the ship is being pulled towards the centre of the universe...

Cast

 * The Doctor - Peter Davison
 * Tegan Jovanka - Janet Fielding
 * Vislor Turlough - Mark Strickson
 * Brazen - Peter Gilmore
 * Norna - Lesley Dunlop
 * Range - William Lucas
 * Plantagenet - Jeff Rawle
 * Cockerill - Maurice O'Connell
 * Orderly - Richard Ashley
 * Gravis - John Gillett
 * Tractators - William Bowen, George Campbell, Hedi Khursandi, Michael Malcolm, Stephen Speed
 * Deputy - Alison Skilbeck
 * Retrograde - Raymond Murtagh

Uncredited cast

 * Captain Revere - John Beardmore (DWM 220)
 * Warnsman - Jim Dowdall (DWM 220)
 * Orderlies - Christopher Holmes, Keith Norrish, Miles Ross, Daniel D'Arcy, John Greening, Barry McKenna, Ian Marshall, John Hamilton Russell (DWM 220)
 * Fighting Retrograde - Steve Emerson (DWM 220)
 * Patient - Barbie Denham (DWM 220)

Crew

 * Assistant Floor Manager - Joanna Guritz
 * Camera Supervisor - Alec Wheal
 * Costumes - Anushia Nieradzik
 * Designer - David Buckingham
 * Incidental Music - Paddy Kingsland
 * Make-Up - Jill Hagger
 * Production Assistant - Valerie Letley
 * Production Associate - June Collins
 * Production Manager - Alex Gohar
 * Script Editor - Eric Saward
 * Special Sounds - Dick Mills
 * Studio Sound - Martin Ridout
 * Studio Lighting - John Summers
 * Technical Manager - Alan Arbuthnott
 * Theme Arrangement - Peter Howell
 * Title Music - Ron Grainer
 * Title Sequence - Sid Sutton
 * Video Effects - Dave Chapman
 * Videotape Editor - Hugh Parson
 * Vision Mixer - Paul Wheeler
 * Visual Effects Designer - Dave Havard

Uncredited crew

 * Assistant Floor Manager - Ed Stevenson (INFO: Frontios)
 * Grams Operator - Gordon Phillipson (INFO: Frontios)
 * Senior Studio Engineers - John Billett, Ron Frith, John Mersh (INFO: Frontios)
 * Visual Effects Assistant - Perry Brahan (INFO: Frontios)
 * Properties Buyer - Robert Fleming (INFO: Frontios)
 * Design Assistants - Maggie Carroll, Matthew Lorrimer (INFO: Frontios)
 * Lighting Chargehand - Terry Smith (INFO: Frontios)
 * Dressers - Frances Miles, Sue Clayton, Derek Sumner, Philip Winter (INFO: Frontios)
 * Make-Up Assistants - Damelza Rogers, Susan Kirkham, Helen Johnson (INFO: Frontios)
 * Production Secretary - Sarah Lee (INFO: Frontios)
 * Floor Assistant - Brenda Thomas (INFO: Frontios)
 * Show Working Supervisor - Ray Davis (INFO: Frontios)

Worldbuilding

 * Turlough makes reference to the Arar Jecks of Heiradi, who had hollowed a huge subterranean city beneath the surface of their planet during the Twenty Aeon War.
 * Turlough's home planet was attacked millennia ago by Tractators — an event that was locked into their ancestral memory. The sight of the Tractators triggers a memory resurgence which causes Turlough to go into catatonic shock. Gradually he recalls more and more of these memories, which allow him to "remember" who the Tractators were, what their goals were — and more importantly, how to defeat them.
 * Gravis is aware of the capabilities of a TARDIS, presumably by reputation.
 * The Doctor asks Turlough to get a portable mu-field generator and some argon discharge globes.
 * Jensen is one of the orderlies.
 * Turlough has two two-corpira coins.
 * The Doctor is about to explain what a Widmanstätten pattern is but gets interrupted.
 * The Doctor compares the TARDIS to a chicken vol-au-vent.
 * Frontios is outside the Time Lords' normal sphere of influence.

Story notes

 * This story had a working title of The Wanderers.
 * For the first time, we see a solid reference to Turlough's home planet, which was attacked millennia ago by the Tractators.
 * The helmets of the Frontios security forces would be familiar to viewers of Blake's 7 as the helmets of Federation troops.
 * The role of Range was originally supposed to be played by, a character actor perhaps best known for his roles in the films Victor/Victoria and Return of the Pink Panther, as well as several guest roles on The Avengers (1961-69). Following a wardrobe test for the part, Arne returned to his flat where he was bludgeoned to death by an unknown assailant. The role was rapidly recast with William Lucas. While a student Arne was in a relationship with, and who was later found floating dead in the Thames, remains a prime suspect, the identity and motive of Arne's killer remains a mystery to this day.
 * The actors playing the Tractators — George Campbell, Michael Malcolm, Stephen Speed, William Bowen and Hedi Khursandi — were credited on-screen for parts two to four, but not in Radio Times.
 * Richard Ashley (Orderly) was credited on-screen for part one, but not in the combined Radio Times cast for parts one and two.
 * Jim Dowdall (Warnsman) remained uncredited both on-screen for part one and in the combined Radio Times cast for parts one and two, despite having dialogue.
 * During breaks in the studio recording, the actors playing the Tractators had to have air pumped into their costumes from underneath as they were insufficiently ventilated for the hot conditions of the studio recording.
 * The cast cited this as a favourite. Peter Davison went so far as to say that the script finally "got hold of how I saw the part of the Doctor". Mark Strickson thought it was "clever and frightening" and gave him a chance to do some real acting.
 * It was originally intended that the Tractators' technology should incorporate human remains, but this was deemed too gruesome for a family audience. However, this idea was used by Christopher H. Bidmead for his novelisation of the story; and was finally taken up on television in The Girl in the Fireplace.
 * Rumours in tabloids, possibly originated by the Doctor Who production team, had it that the TARDIS would be removed from the show from that story on, much like the sonic screwdriver was. Peter Davison theorised in a DVD extra that this was never meant to actually happen, and was just one of John Nathan-Turner's public relations moves.
 * The Tractators were inspired by the woodlice which had infested a former residence of Christopher H. Bidmead's.
 * Part one badly overran, forcing Ron Jones to make a number of trims. Much of the excised material involved Cockerill and explored his deepening sense of rebellion. Also cut was a scene in which Tegan and Turlough return to the TARDIS and find it surrounded by curious colonists, which explains Turlough's later quip that the time travellers have lost their "news value".
 * A cut scene in part three revealed that the voices of the Doctor and Tegan have echoed through the Tractators' tunnels, explaining how the Gravis is aware of the Doctor's intelligence.
 * ,, Jim Broadbent, Tom Chadbon, Maurice Colbourne, Forbes Collins, , , John Hallam, Del Henney, Philip Jackson, Alan Lake, Terry Molloy, Tony Osoba, Edward Peel, Donald Sumpter and Stephen Yardley were considered for Cockerill.
 * Peter Davison and Eric Saward both criticised the slowness of this serial on the DVD commentary, arguing that the story could have been concluded in half the time.
 * Barrie Dobbins was the serial's original designer, but was replaced by David Buckingham due to concerns about his mental health. Dobbins committed suicide shortly thereafter.
 * Ron Jones was unhappy with Dave Havard's design for the excavation machine, so he filmed around it as much as possible.
 * During rehearsals, the BBC announced that Colin Baker had been cast as the Doctor.
 * William Lucas suffered from the flu during production.
 * Shooting wound up badly behind schedule, leaving little margin for error. At one point, Jeff Rawle put his foot through a step, and was astonished that the take was deemed acceptable.
 * Despite the difficulty in realising the Tractators, the monsters had proved popular with the production team and Eric Saward wrote to Christopher H. Bidmead and proposed a new story which would team them with the Master.

Ratings

 * Part one - 8.0 million viewers
 * Part two - 5.8 million viewers
 * Part three - 7.8 million viewers
 * Part four - 5.6 million viewers

Filming locations

 * BBC Television Centre (TC6), Shepherd's Bush, London

Production errors

 * In the opening scene, as Captain Revere sees the earth moving beneath him, the fingers of one of the technical crew are visible giving it a helping hand.
 * When Tegan traps Brazen in the medical unit, she puts a bar across the middle of a door handle. By the next scene it has moved to the top of the handle.
 * In this same scene, the handle of the door on the left is clearly made of cardboard and not metal, as it bends and flops about.
 * The Doctor refers to the TARDIS as a "Type 40 Time and Relative Dimension in Space", as Susan Foreman did in An Unearthly Child, rather than Dimensions, as had been retconned.

Continuity

 * The story of the Doctor taking the Gravis to Kolkokron is told in PROSE: Life After Queth. Stories taking place after the Doctor transports the Gravis but before returning to Frontios include PROSE: Perfect Day, Keeping It Real and AUDIO: Time in Office.
 * AUDIO: Excelis Dawns occurs between the wrap up of this story and the scene which continues into TV: Resurrection of the Daleks.
 * Others also left Earth to form after an exodus from Earth. (TV: The Ark)
 * When Plantagenet asks the Doctor if he was the one who saved his life, the Doctor simply responds, "not a word to the Time Lords", referencing their non-interference policy (TV: The War Games et. all) and his presence at a point in the far distant future.
 * The Sixth Doctor would encounter the Tractators again in the English village of Hollowdean in the early 1980s, millions of years prior to their activities on Frontios. (AUDIO: The Hollows of Time)
 * The time corridor in which the TARDIS is caught as they leave Frontios is soon revealed to be controlled by the Daleks. (TV: Resurrection of the Daleks)

Home video and audio releases
This story was released on video alongside The Awakening. Release dates were:

Region 2: March 1997

Region 1: March 1998

Region 4: March 1998

DVD release
This story was released as Doctor Who: Frontios.

Released: Region 2: 30 May 2011

Region 1: 14 June 2011

Region 4: 7 July 2011

Special Features:
 * Audio Commentary by actors Peter Davison (the Doctor), Jeff Rawle (Plantagenet), John Gillett (the Gravis), script editor Eric Saward and special sounds designer Dick Mills
 * Driven to Distractation - Making Of with cast and crew
 * Deleted and Extended Scenes
 * Isolated Music Score
 * Photo Gallery
 * PDF materials (DVD-Rom - PC/Mac) - Radio Times Listings

It was also released as issue 100 of Doctor Who DVD Files.

Digital releases
The story is available for streaming in Canada & the US through BritBox or Amazon Instant Video in the UK. It is also available to download through iTunes.