Time - Flight ( TV story ) Time - Flight was the seventh and final story of season 19 of " Doctor Who " . For those interested in viewing statistics , it ' s a highly significant story , because different surveys of audience reaction have produced widely varying results . The most statistically valid of these measures — the actual television ratings — show that episode one was the most successful episode in John Nathan - Turner ' s entire producer ship . The 26th - most - watched episode of British television in the week of initial transmission , it was the only time he cracked the top 30 . However , the story also shed about two million viewers from beginning to end . Fan opinion — which , of course , is never the subject of truly valid statistical investigation — has changed dramatically over the years . Those who responded to DWM 69 ' s season 19 poll held it in reasonably high regard , placing it as the fourth - best serial of the year , ahead of " Castrovalva " , " Four to Doomsday " and " Kinda " . Decades later , those fans responding to DWM 413 ' s " Mighty 200 " poll in 2009 cited it as the 196th of the 200 stories that were then produced . Similarly , fan response to the " first 50 years " poll in DWM 474 in 2014 cited it as the 237th out of the 241 stories up to that point in time . A part of the explanation for this massive shift in negative momentum may be that fan leaders such as Paul Cornell and David J . Howe savaged the story in references works like " The Discontinuity Guide " and " The Television Companion " , whose influence multiplied when BBCi , and later BBC Online , incorporated those opinions into the official " Doctor Who " website . Thus people skimming the official site in the 2000s and 2010s could well believe that opinion of the BBC runs along the lines of , " Somebody , somewhere should have thrown this script in the bin the moment it had Concorde crash landing in Jurassic England . . . " Narratively , the story contained what appeared , at the time of transmission , to be the final appearance of Tegan . Tegan was left behind at Heathrow Airport at the conclusion of the episode . This appeared to end her story , since many stories that year had begun with an on - going attempt to get her back to Heathrow . She would later return at the beginning of the next season . It also serves as Adric ' s last regular appearance ( albeit only as a hallucination ) , after his death in the previous serial " Earthshock " . This episode followed directly after the death of Adric and attempted to show the TARDIS crew coping with his loss , but noticeably downplayed their reactions , coming off a story that ended on the highly emotional bombshell that Adric was killed . The Doctor hastened Tegan and Nyssa to move straight from their grief to acceptance , seeing as how Adric would not want the group to mourn him . He also noted Adric ' s life wasn ' t wasted ; Adric died trying to save others , just like his brother , Varsh , and had made a choice in sacrificing himself , this being what he wanted . Synopsis . While investigating a vanishing Concorde at Heathrow Airport , the Doctor and his companions are thrown millions of years back in time , when a mysterious alien called Kalid is trying to control the ancient powers of the Xeraphin . Plot . Part one . On a regular flight from New York to London , a Concorde designated Golf Victor Foxtrot ( GVF ) is nearing Heathrow Airport when its signal breaks up . All trace of the aircraft is lost — the Concorde has disappeared . Having dropped Scott , Briggs and Berger off safely in their own time , and with the Cyber - fleet dispersed , the Fifth Doctor , Nyssa and Tegan prepare to depart 26th century Earth . When Tegan try to persuade the Doctor to travel back and rescue Adric from the doomed freighter , the Time Lord tells her and Nyssa that , even with the TARDIS , there are laws of time even he cannot break and they should never ask him to do such a thing again . After this , the Doctor explains that they must accept that Adric is dead , which Nyssa and Tegan finally do , even though they will miss him . The Doctor suggests a visit to the Great Exhibition of 1851 to cheer them up , towards which they depart . En route , they encounter heavy turbulence and are forced to materialise . The Doctor , Nyssa and Tegan find themselves hovering over a runway at Heathrow . The dematerialise again and end up in a terminal at Heathrow where , thanks to the Doctor using his UNIT credentials , they are enlisted by Department C19 to help in the investigation of the missing aircraft . The trio board a similar Concorde , Golf Alpha Charlie , and follow the same flight path to try to discover the cause of the disappearing Concorde . The TARDIS is stowed on board . Stapley , the Concorde ' s captain , and his senior crew welcome them aboard . The Doctor finds traces of disturbance . The Concorde starts a planned decent and lands . Leaving the Concorde , everyone believes that they are safely at Heathrow , they find they have travelled a hundred forty million years into the past . The crew believe they have landed in modern Heathrow . The Doctor and Nyssa urge them to challenge this perception and realise the reality of the empty landscape . It is distorted by huge amounts of psychokinetic energy . They spy Victor - Foxtrot on the empty plain . Beyond it is an impressive citadel in the far distance and the remains of an alien spacecraft . The Doctor and his friends find the crew and passengers of the first Concorde . They are moving his TARDIS toward the Citadel on the instructions of an alien entity . Everyone is totally immersed in the illusion of a modern Heathrow — all , that is , save one passenger , Professor Hayter . He has resisted the illusion . Andrew Bilton and Roger Scobie , see members of GVF ' s crew and passengers carrying the TARDIS towards the Citadel and investigate . Bilton and Scobie are captured and transported to the Citadel where they are hypnotised . The GVF crew ' s progress is marshalled by the Plasmaton s - blobs of protein from the atmosphere , assembled from random particles that are held together by the same kinetic energy . Part two . The force in charge of this strange domain is Kalid . He seems to be an oriental mystic . He uses a glowing green globe to control psychokinetic energy and shape the prehistoric landscape of Earth . Nyssa has a particular empathy with this energy . She starts getting visions and hearing voices . They are unwelcome to Kalid . He tries to cut her off from the others with a protoplasmic shield . Tegan stays with Nyssa while the Doctor ventures on to the Citadel with Hayter and Stapley . There they find the crew of Victor - Foxtrot , blindly trying to remove the walls of a sealed chamber . Stapley and Hayter try to free the others from the mental illusion . The Doctor heads to the Citadel and meets Kalid . The green - tinged magician has evidently brought a slave force to prehistoric Earth . He taps into the psychokinetic powers of the place and uses the energies to menace Hayter , Stapley and the others to try to secure the Doctor ' s cooperation in entering his TARDIS . This exertion has broken Kalid ' s mental hold over the plasmatons around Nyssa . They disperse . Nyssa and Tegan follow the former ' s instincts and proceed through the Citadel . Along their way , they come across Adric , previously believed to have been killed when the interstellar freighter he was trapped on crashed into Cretaceous Earth . Adric warns that he will die again if Nyssa and Tegan continue onwards , and urges them to retreat . However , Nyssa outs Adric as a mere apparition upon noticing his star - shaped badge , which the Doctor destroyed when he lethally grinded it into the late Cyber - Leader ' s ventilation unit aboard the TARDIS . Knowing this , they press on , causing " Adric " to dissipate . Continuing on , they encounter apparitions of the Melkur ( who was destroyed on Traken ) and the disfigured Terileptil ( who was burned to death in 17th - Century London ) ; Nyssa and Tegan respectively denounce the villains ' existence and continue . Eventually , they enter a chamber in the Citadel that has been closed to Kalid and the mentally deluded passengers . Nyssa throws an artefact into the centre of a tank - like structure in the centre of the sealed room . The results are immense . Kalid ' s mental channelling is interrupted and he collapses in agony . His disguise falls away to reveal the Master . Part three . The Master is trapped in this time zone . He is looking for a way out and needs a new source of power for his TARDIS . The power in the closed chamber could be it , but the passengers are taking too long to get to it . He forces the Doctor to give him the key to the TARDIS and steals the craft to try to enter the chamber another way . The Doctor and Hayter rush to the chamber to reach it first . As they do , the Concorde passengers finally break through the wall . Inside , the Doctor and Hayter are reunited with Nyssa and Tegan . The sarcophagus at its centre holds a being of immense power . However , it has a split personality . It has let itself be used by the Master and Nyssa . Nearby are small shrunken bodies . The Doctor identifies them as the Xeraphin , a race of ancient beings believed destroyed during the Vardon - Kosnax War . Instead , the entire race seems to have transformed itself into a single gestalt intelligence in the tank . It has phenomenal psychic abilities . Hayter sacrifices himself to the creature to let it communicate . He is absorbed into the entity . The Xeraphin manifest as Anithon . It explains the entity came to Earth to escape the war . It came in the crashed spaceship on the plains . The Xeraphin were so harmed by radiation that they shed their bodies and became a single entity . The Xeraphin built the Citadel and planned to re - emerge from the sarcophagus once the radiation danger was over . The Master ' s arrival disturbed the balance . The gestalt has developed a split personality of good and evil . Each side competes for their tremendous power , but yearns to become a proper species once again . The Doctor has left the coordinate override switched on , and Captain Stapley has performed sabotage . The TARDIS won ' t take the Master into the central chamber . His next gambit is to build an induction loop to remotely access the sarcophagus and exert his will over it . The bad Xeraphin responds . Within moments the sarcophagus is in the Master ' s TARDIS , a new power source . Part four . The Master tries to flee in his ship , with those passengers still deluded with him as slaves . He leaves the Doctor and his friends stranded . However , due to the sabotage by the Captain , the Master cannot leave prehistoric Earth . After some chaffering over missing parts , the Doctor has all the passengers released and some parts taken from his own TARDIS . In return , the Master gets a new temporal limiter . Everyone leaves prehistoric Earth . The second Concorde is made serviceable . It carries Stapley , his crew and the passengers from the other Concorde to Heathrow . The Doctor reverses the track of the time contour and brings the plane back to Heathrow with his TARDIS . The Doctor programmed the temporal limiter he gave the Master to arrive after he did . When the Master tries to land , the Doctor ' s TARDIS is already in the spot . He bounces the Master ' s TARDIS away . The evil Time Lord is sent to modern - day Xeriphas , where the Doctor hopes the Xeraphin will exact their revenge . In a rush to leave , the Doctor and Nyssa head off in his TARDIS . They assume that now Tegan is back in her beloved Heathrow she will be happy to stay . Her sorrow as she sees the TARDIS dematerialise tells a different story . Story notes . Ratings . Part one marked the last time the classic series exceeded 10 million viewers . By the final seasons viewership had dropped to the 3 - 4 million range . Discounting the 1996 TV movie , a rating exceeding 10 million viewers would not be achieved again until " Rose " . Home video and audio releases . DVD releases . This story was originally released in a double - pack with " Arc of Infinity " in Region 2 and Region 4 , but released singly in Region 1 . The R2 and R4 cover art of this story and " Arc of Infinity " shows the " Peter Davison Years " as 1981 - 1984 . All other Davison - era releases have claimed the years as 1982 - 1984 , in deference to the January , 1982 broadcast of " Castrovalva " . However , there is justification for calling the era 1981 - 1984 , as that ' s the period of time Davison actually worked on the programme . Like Jon Pertwee , Davison fell victim to the BBC ' s decision to push back the premiere of his first series to the start of the new calendar year . Neither actor is generally credited for their first year on the job , making their eras appear a little shorter than they actually were . While Pertwee only filmed about half of Season 7 in 1969 , almost everything of Season 19 was filmed in 1981 . Indeed , Davison ' s first work on the series — his regeneration scene — had been filmed on 9 January 1981 , almost a full year prior to the release of " Castrovalva " . Ironically , the only part of Davison ' s initial year " not " filmed in 1981 was " this " story . All told , Davison ' s time in front of the cameras as the Doctor lasted from 9 January 1981 to 12 January 1984 — almost precisely the three - year tenure he had been advised by Patrick Troughton to undertake , and the length of his three - year contract . Contents : Notes :