The Mutant Phase ( audio story ) It was an early example of a non - original piece of " Doctor Who " fiction published by Big Finish . It was in fact a remake of an unlicensed audio drama published by Audio Visuals . This was , according to the fictional timeline , the first performed story to feature an encounter between either the Fifth Doctor or Nyssa and the Dalek s . Publisher ' s summary . In the 22nd century , the Dalek s have occupied planet Earth . By the 43rd century , only a handful of human s survive . Still further into the distant future , a Thal scientist must choose whether to betray his heritage , or see the universe destroyed . When the Doctor and Nyssa find themselves trapped in this deadly chain of events , they must decide who their real enemies are . What is certain , however , is that no matter where the Doctor turns . . . his arch enemies , the Daleks , will be waiting for him . What could possibly be worse than that ? The Mutant Phase . . . Plot . Episode one . On the starship Dyoni , Professor Ptolem completes his audio survey log . An odd echo is heard as he speaks . The ship is sweeping the trade routes and Ptolem reports that every planet they have surveyed is devoid of life . He determines that some force or thing has destroyed everything . He thinks it must be some kind of natural disaster that caused all this . As he tries to come up with a solution , he is interrupted by Commander Ganatus who tells him they ' ve picked up something on the long range scanners . The scanners have picked up a life form heading straight for them at incredible speed , three times their maximum . The life form turns out to be a group of over 100 , 000 , 000 , 000 units making up the whole , flying in close formation . Ganatus decides it ' s a swarm . The ship decides to get out of the area but they realise that swarm will overtake them . They cut off the engines and divert all power to their defence screens , hoping for the best . The swarm hits them and the ship is caught in the wake , flying out of control . When the ship is finally freed , the swarm has vanished . Ganatus realises that they are in space around Skaro . Nyssa is making repairs on the TARDIS audio systems for the proximity alarm to avoid a problem like they had when she and the Fifth Doctor visited Alaska . The alarm goes off and the TARDIS is thrown into a Time corridor . They realise they are being drawn towards the end of it . The TARDIS isn ' t able to break free but they can bounce off it . The land roughly in a large cornfield . The Doctor says he has no idea where they are , as the time corridor interferred with the TARDIS systems . Nyssa notices a large number of wasp s buzzing around them . Nyssa gets stung in the arm by one of them . She insists she ' s fine , but the Doctor looks at it anyway . Suddenly , they hear a loud whoosh and a blur overhead . Nyssa thinks that ' s a sign of some kind of civilisation . The Doctor decides they should explore and eventually , they ' ll come out of the field . Now on planet Earth , Ptolem contacts Ganatus through a communicator . Weather conditions are making the transmission difficult . Ptolem is trying to get back to their base but is over the human ' s bunker . Ptolem wonders if they saw him , but Ganatus isn ' t worried . In an underground bunker , Albert is on a pile of books looking through a periscope . Delores asks if he ' s found anything . He did see someone stumbling around but then disappeared in the storm . Delores asks Albert if he is going to help them . Albert replies that they have with food and medical supplies . Delores is concerned that if the aliens blast off again , they won ' t have any more food or supplies . Albert says they ' ll face each situation as it comes . She insults him and leaves . Nyssa and the Doctor continue to walk through the field . Another spaceship passes overhead . They decide to walk in that direction . Suddenly , they hear gunfire and grenades . They decide to head back towards the TARDIS . Ptolem arrives at their base , bringing back more soil samples . Ganatus laughs , telling Ptolem that the Doctor has finally been spotted on the time track . The Doctor and Nyssa crouch down in the field , lost and unable to find the TARDIS . The Doctor wishes he ' d brought his tracker . They try to get their bearings . Nyssa finds a body lying in the field . After some investigation , they determine that he was an American sheriff from the state of Kansas . Nyssa notices that he has scars on his head and bullet hole in his back . The Doctor looks for a warrant card and using the date of the card ( 2139 ) , the Doctor is able to determine the year . He tells Nyssa that the scars on the sheriff ' s head are from alien technology which was grafted right on to his skull . The Doctor goes on to say that he was under the control of an alien intelligence and was shot in the back and the technology removed from him . He tells her that they are on Earth in 2157 and they have to find the TARDIS . Ptolem activates the time track and determines that the Doctor is in 2158 . Ptolem has read the Doctor ' s history and knows he won ' t be staying there long . The Doctor and Nyssa are moving quickly through the field , trying to avoid any gunfire and find the TARDIS . They hear a shotgun being cocked and a voice telling them not to move . Nyssa notices he is another sheriff , the Doctor adding that this one comes with alien technology . The Sheriff asks if they are with the other freedom fighters . The Doctor says no , but they are hiding in the " blue box over there " . The Sheriff doesn ' t believe him and contacts control for to report their capture . Nyssa sees that the wasps sting him and he doesn ' t seem to notice . The sheriff requests backup . A spaceship lands nearby . Nyssa asks the Doctor what it is . A Dalek comes over to them demanding they identify themselves . This Dalek has been damaged in battle . It demands they identify themselves and then determines they have escaped from the work camps . The Doctor tells Nyssa to get ready to run to the TARDIS . The Dalek demands to know what a TARDIS is . They run to the TARDIS , being fired on by the sheriff and the Dalek . The TARDIS dematerialises and explains to Nyssa that he ' s met the Daleks before , but they haven ' t met him yet . Nyssa is complaining that the sting is hurting her arm again . As she goes for the medical kit , the Doctor realises that by dematerialising , they are back in the time corridor again . Ptolem tells Ganatus to check and confirm that the Doctor is back in the time corridor and is in transit . Nyssa is unable to set the controls and can ' t get the destination to register . She says it ' s a shame he can ' t do his bouncing trick with the corridor again . The Doctor says that it doesn ' t matter , wherever they land there are sure to be Daleks there . Ganatus says that the Doctor ' s arrival is imminent . Ptolem says they ' d better meet him . Ganatus says that they really don ' t have a choice . The Doctor tells Nyssa that they are falling into a trap set by the Daleks . Nyssa says that the should put up a fight to put some space between them and the Daleks . The Doctor tries to dematerialise putting them in a different place than they ' re supposed to be . Ganatus says the time corridor has been activated . Ptolem asks if Ganatus ever wonders why they ' re doing this . He says they ' re doing what has to be done . The time corridor stops and a Dalek exits asking for a report . Ptolem tells the Dalek that the Doctor will be arriving soon . The Dalek says that the Doctor will soon be in their power . The Doctor asks if there is any change in the special coordinates . Nyssa is unable to tell from the instruments . The Doctor decides to risk it and materialises . Delores tells Albert that it was lucky that the Thal s showed up and wonders if they do this kind of thing all the time . They hear the TARDIS materialising and decide to go investigate . Albert thinks it might be the Thals again . The Doctor and Nyssa exit the TARDIS and she complains about the wasp sting . Nyssa says they appear to have materialised inside a structure . They don ' t see any Daleks and decide to go investigate . The Daleks return and ask Ganatus where the Doctor is , as the time track says he should have arrived . Another Dalek reports that the TARDIS did arrive at the right time , but he has altered the coordinates . The first Dalek asks if the TARDIS can be found . They say that the Doctor is somewhere on the planet and they will begin a search . The Doctor and Nyssa realise they are underground and the structure is under tremendous pressure causing cracks in the floor and walls . They decide that they have to find another way out , since if they dematerialise , they ' ll wind up back in the time corridor . Nyssa hears footsteps coming towards them and wonders if its more of the Robomen . The Doctor tells Nyssa that the Dalek invasion of Earth was foiled in 2167 . Delores finds the Doctor and Nyssa and mentions to Albert that they aren ' t Thals . The Doctor asks if they said " Thals " . The Daleks decide to open the time corridor and return to Skaro . One of the Daleks begins speaking oddly and has trouble controlling itself . Its casing cracks and the other Daleks begin screaming about the Mutant Phase and seeing the Dalek is infected decide it should be exterminated . Ptolem pleads with the Dalek that the infected Dalek should be examined . The Daleks try to kill it as Ptolem and Ganatus watch the creature grow and mutate . Episode two . Ptolem takes the mutant creature from the Dalek casing . He wants to study it at the larva stage . The Dalek states that now that the Doctor has been captured , Ptolem ' s research is of no importance . Ptolem tells the Dalek that the Doctor isn ' t captured yet and he was granted full authority to do what is necessary to get rid of the Mutant Phase . Albert tells the Doctor and Nyssa that the Thals have been helping the humans . When asked about the Daleks , neither Albert nor Delores knows anything about them . Albert asks if they ' re friends of the Thals . The Doctor asks for an explanation of what ' s been happening on Earth . Delores says there was a global disaster about 30 years ago . Delores ' mother was one of the survivors . Nyssa asks what caused the disaster . Delores and Albert decide to take the Doctor to see Professor Karl Hendryk , saying he ' s the only one who understands what happened . Albert notices Nyssa ' s arm . They decide to have Albert look at the arm while Delores takes the Doctor to see Karl . Ganatus tells Ptolem that the creature is secure in a containment field . They discuss what will happen to them if they can find a cure , Ganatus thinking they will probably be extermined . Ptolem says that he has an " insurance plan " but before he ' s able to tell Ganatus about it he notices the creature dying . They feed it some nutrients and it immediately begins to improve . They have the defence screen power increased , saying they ' re going to see marked improvement very quickly . Ptolem leaves to go back to sleep . Ganatus watches the creature . The Doctor asks Delores how many survivors are in the caves , she tells him about 20 - 25 people . She tells the Doctor that there aren ' t any other groups of survivors , as the Thals did a planetary sweep and were surprised to find them . Delores says that she doesn ' t hold much hope for the human race . Karl told her there are other humans out there , but if they ' re there why haven ' t they come to help ? Albert takes Nyssa to a room to work on her arm . He gets the medicine box . He begins to act oddly and politely excuses himself . Nyssa sighs and works on the wasp sting on her own . Dolores takes the Doctor to Karl ' s room . He enters a dark room , calling out for anyone . Trying to find a light switch , the Doctor is told that there is no light . Karl invites the Doctor into the room to sit down . Nyssa notices the sting is getting worse . She finishes and goes looking for Albert . She hears him talking to someone , mentioning the TARDIS . Karl asks if the Doctor is a Thal , but decides he ' s not when the Doctor begins asking questions about what happened . He tells Karl that he ' s been brought here by the Daleks and asks if he ' s ever heard of them . Karl remembers something about a war with them . The Doctor wonders if the Daleks are responsible for what happened on Earth , Karl tells him no and asks the Doctor to describe the Daleks to him . Karl says it was not the Daleks who caused the destruction of Earth . He says he wants to show the Doctor something and takes him to another room . Ganatus notices that the rate of growth of the creature is increasing . He says that it ' s also showing signs of the maturing process . The creature is moving out of the larva stage . Karl takes the Doctor to a room and gives him a flashlight . In the room is one of the creatures , dead . The Doctor says it is insectoid and over 100 metres in length . Karl says to imagine hundreds of them flying across the sky . He says when they left , they sucked the life out of the planet taking all the minerals , nutrients and micro organisms out of the soil . He says that any defence was useless and the sucked up the destructive forces used against them . Karl tells the Doctor that they died suddenly . The Doctor asks how they died out and Karl didn ' t know . That one day they just started to die , that there was nothing left to sustain them . The Doctor wonders what the connection is with these creatures and the Daleks . A Dalek reports to the Dalek Supreme that mutant phase on Skaro is increasing . Mutant creatures are assaulting the defence barriers . They continue to divert all power to the defences but collapse is imminent . They absorb energy from the defence barriers . A report comes in from the Daleks on Earth who tell the Dalek Supreme that the Doctor has been located . He demands that a time squad be dispatched to capture him . Nyssa finds Delores , demanding to see the Doctor . Delores demands to see Albert . Nyssa tells Delores that she heard Albert in communication with the Daleks . Delores has no idea what she ' s talking about but takes her to see the Doctor . An alarm sounds waking Ptolem up . Ganatus walks into him room telling him the Daleks are here , they ' ve found the Doctor . The Daleks want Ptolem and Ganatus to be with the Dalek time squad . Karl asks if he has answered the Doctor ' s questions . The Doctor wants to know why Karl doesn ' t trust the Thals , saying they are the most peaceloving creatures in the universe and sworn enemies of the Daleks . The Doctor determines that something is very wrong and not how it should be . Heading down the hall , Delores says that Karl would have taken the Doctor to see the " monster " . Enroute , they run into Albert . Nyssa is furious , asking who he was talking to and that she heard him telling someone about the Doctor and the TARDIS . Albert thinks there ' s been a misunderstanding . She demands that Albert get out of their way . He grabs Nyssa ' s arm , keeping her there . Nyssa hits Albert knocking him to the floor . Albert tells them that the Doctor and Nyssa must not be allowed to escape in the TARDIS . Delores has no idea what Albert is talking about . He demands that she obey him . Delores responds by punching Albert and they head back to find the Doctor . Ganatus says the creature is still growing . The Daleks tell them that the creature should be exterminated . Ptolem says that it ' s a vital part of his work . The Dalek tells him that they must proceed to the bunker and the Doctor is there . Ganatus says the weather is too harsh for them to go and they must wait . The Dalek says he has orders to exterminate them if they do not obey . Ganatus tells Ptolem that it sounds like the Daleks mean it this time . Nyssa finds the Doctor and tells him that they have to get back to the TARDIS . Delores tells the Doctor that Albert is acting weird and Nyssa thinks he ' s working for the Daleks . The Doctor agrees saying the only safe place for them is in the TARDIS . Nyssa sees the creature , asking what it is . The Doctor doesn ' t answer and they head back to the TARDIS . The creature continues to grow and more power is diverted to the defence screen as the it attempts to break through . Ptolem and Ganatus continue walking through the storm heading towards the humans ' bunker . Ptolem wonders how they found the Doctor and Ganatus replies saying that if they have found him , all their troubles will be over . Ptolem reluctantly agrees . The Dalek tells them to hurry . Delores leads the group towards the TARDIS . The Doctor asks how Nyssa ' s arm is and she replies that it ' s getting worse . As they walk , the group comes upon a wall that wasn ' t there before . Delores is sure they were going in the right direction . The Doctor notices that it ' s not really a wall but a bulkhead door . Delores concludes that Albert must have activated it . Albert then walks in holding a gun . He tells them to stand still . Delores wants to know what they ' re waiting for . The Doctor has a good guess as to what it is . They arrive at the bunker . The Daleks go in first followed by Ptolem and Ganatus . The Dalek leader tells the others to activate heat scans to find the Doctor . The Doctor asks Albert how the Daleks are controlling him . The Doctor continues to walk towards Albert , still questioning him . The Doctor says that if the Daleks had wanted him dead , Albert would have done it already . Albert fires his gun and Karl shoots Albert , grazing his scalp . Nyssa opens the bulkhead door and finds the TARDIS . He tells Nyssa to get inside and suggests that Karl and Delores do the same . The Daleks enter the base , firing their weapons . Karl returns fire and is exterminated . Albert tells Nyssa not to move and grabs her again . Delores punches Albert to get him to let go . The Doctor enters the TARDIS . The Daleks demand that he leave the TARDIS otherwise he will exterminate the women . The Doctor refuses . Ptolem and Ganatus show up and Ptolem then attempts to persuade the Doctor to leave the TARDIS . He asks for a chance to explain and is convinced afterwards , the Doctor will help the Daleks . Ptolem tells him that he can ' t take off because of the time corridor . The Doctor demands that Nyssa and Delores be allowed to enter the TARDIS and then Ptolem can explain . The Daleks find that unacceptable and exterminate Delores . The Daleks threaten that if the Doctor doesn ' t surrender , they will exterminate Nyssa . The Doctor exits the TARDIS saying " I surrender " . Episode three . " to be added " Episode four . " to be added "