Frontios ( TV story ) Frontios was the third story in the twenty - first 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 . Tabloid rumour was that the producers of the show intended to remove the TARDIS from the show completely . However , in the Frontios DVD release commentary , script editor Eric Saward indicated that this was never a possibility . 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 . What lies beneath the surface , dragging its victims down ? Plot . 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 . 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 . 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 deduce s 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 Tracatators 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 wave guide 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 Plantaganet 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 . . . 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 : It was also released as issue 100 of " Doctor Who DVD Files " . Digital releases . The story is available for streaming in the US through Hulu Plus or Amazon Instant Video in the UK . It is also available to download through iTunes .