Silver Nemesis ( TV story ) Silver Nemesis was the third story of Season 25 of " Doctor Who " , and the twenty - fifth anniversary special . To commemorate this , John Nathan - Turner chose silver as a theme for the story . Kevin Clarke contacted Andrew Cartmel and asked if he could write a script for the series . The only slot left was the special and Clarke claimed to have the perfect script . In fact , he didn ' t , but when he met with Nathan - Turner , he proposed to ask the question : who is the Doctor ? ( DOC : " Industrial Action " ) Another theme Nathan - Turner wanted was royalty , and so Windsor Castle was introduced . He even sent to , asking him if he wanted to appear . He declined , but JNT took it to be that he had wanted to appear , but Queen Elizabeth II had stopped him doing so . In the press , stories circulated that he would be making an appearance and the palace was forced to release a statement denying it . Arundel Castle doubled for Windsor , and several figures from the history of " Doctor Who " turned out to play tourists , including Vere Lorimer , Nicholas Courtney , Fiona Cumming , Peter Moffatt and Kevin Clarke himself . Synopsis . The arrival of a mysterious comet heralds impending danger from enemies both old and new . As Ace helps the Doctor defend Earth , she is confronted with a dangerous question . . . " Doctor Who ? " Plot . Part one . South America , 22 November 1988 : In an office full of Nazi imagery , a man looks at a computer screen displaying details on which he sees " Landing Location , Windsor , Grid Ref : 74W 32N , November 23 , 1988 " . Outside , his superior , De Flores , is about to shoot a parrot with a bow and arrow when the man informs him about the news . Windsor , England , 1638 : A finely dressed woman is shooting pigeon s with a bow and arrow whilst her manservant looks on . In her house , an elderly gentleman mathematician is performing complex calculations . The woman enters and demands to know how long his work will take , but he is too engrossed in his work to answer her . She goes to the fireplace and , picking up a poison ed arrow , hands it to her manservant and tells him to put it with the others . He inquires after a silver arrow , and she replies that she will deal with that arrow personally . Back in the Nazi office , De Flores addresses a group of followers , telling them they are at the turning point of history . He proposes a toast to the fourth Reich , before taking a silver bow from a display case , preparing to board an aircraft . In space , a comet is seen from which a glowing energy emanates . . . Back in Windsor , the mathematician finally reveals the result of his calculations to the woman , telling her that the Nemesis comet circles the earth every 25 years , and its decaying trajectory means that it will eventually fall to Earth from the point where it originally departed — the meadow outside . This will occur on 23 November 1988 . At a jazz performance by Courtney Pine , the Seventh Doctor and Ace relax and enjoy the music . Ace ' s newspaper — namely the " Daily Mirror " — has a story about a comet heading to Earth , but she is more interested in the football results . The Doctor hears a bleeping from his pocket watch and wonders of what it is trying to remind him . Pine ' s performance ends to applause and Ace asks him to sign a tape for her . As they head back to the TARDIS , a concealed marksman raises a gun towards them . At the sound of gunfire , Ace and the Doctor duck down and retreat quickly towards the TARDIS , but have to jump in the river to escape their pursuers . Two men arrive wielding guns and wearing headsets , but , assuming they must have got their targets , they leave again . The Doctor and Ace then struggle back on to the riverbank , safe now . In 1638 , the mathematician dreams of great inventions that he could discover . The lady tells her servant to bring forth the potion , and he replies that they only require the final ingredient , human blood . They look meaningfully towards the mathematician . . . The Doctor fetches out a new tape deck that he has built to replace the one of Ace ' s that had been destroyed by the Dalek s . This one , however , can do much more than play tapes . The Doctor tells Ace that his reminder had a terminal rating , meaning some planet somewhere is facing imminent destruction , and an image of the planet Earth appears on the tape deck . In 1638 , the woman and her servant drink their potion and are surrounded by a glowing miasma . They begin to travel forwards through time . They appear in present day Windsor in the middle of a crowded cafe . The Doctor admits that he has known about the possible destruction of Earth for 350 years . He and Ace take a quick trip in the TARDIS to Windsor Castle . In its basement , the Doctor tells Ace he is looking for a silver bow . As the comet finally hits Earth , the woman ' s arrow begins to pulsate with light . In the castle , the Doctor and Ace feel the force of the impact . The Doctor tells Ace that it is the return to Earth of a comet called Nemesis , and then reveals that it was he who had launched it into space in the first place . Led by their glowing bow , the group of Nazis heads towards the comet in a van . De Flores is in no rush to retrieve the Nemesis yet , as the comet will be too hot due to its descent through the atmosphere . He tells his soldiers they will wait in a hotel , leaving British police to guard the site , unaware of the true power of the Nemesis . In the castle , Ace finds a card telling the history of the bow , relating to how it disappeared in 1788 , and that unless a place is kept in the castle for its return , the entire silver statue will return to destroy the world . The Doctor tells her that the statue has indeed returned with that purpose . At this point , the lights dim , and Ace thinks it is a power cut . Travelling back in time to 1638 , the Doctor and Ace go to the time travelling woman ' s house in Windsor . Seeing the corpse of the mathematician , the Doctor hurriedly covers it with a cloth so that Ace does not see it . The Doctor sees the mathematician ' s calculations and is impressed that he had been able to work out when the Nemesis comet will return to Earth , only months since the Doctor ' s previous visit . The Doctor reveals that the woman — Lady Peinforte — made the Nemesis statue , depicting herself , out of a silver metal that fell to Earth in the meadow outside her house . The Doctor sees a chessboard , and notes that the game is going rather badly . He tells Ace that Peinforte managed to travel forward in time to 1988 using the arrow and a rudimentary knowledge of time travel , but mostly " black magic " . He says that she has a nose for secrets . The Doctor tells Ace the statue is made of a living metal — validium — which is capable of great destruction . Peinforte and her servant Richard withdraw from the statue to assess the strength of the police guarding it . The police are having their own problems . Their radios are not working ; the batteries are dead . Around the comet crash site , vents emerge from the ground spewing gas , causing the policemen to choke and fall unconscious . The TARDIS materialises outside Windsor Castle in 1988 . The Doctor and Ace follow a group of tourists on a guided tour . Seeing a no entry sign , they sneak into the castle . Hearing the bark of dogs , they see a woman coming towards them with several corgi s . The Doctor recognises the woman , but can ' t immediately place who she is . Ace realises that it is Queen Elizabeth II and drags him into hiding . However , when she tells him who it was , he races after the Queen , saying they need the armed forces and police on their side , and who better could they ask ? The Doctor and Ace are seized by security guards before they can get anywhere near the Queen . The Doctor informs the guards that they got into the castle by travelling in time and space , but the guards are incredulous . The Doctor tells them the fate of every living person is in danger , but the guards do not believe him . The Doctor dons a pair of over sized glasses and , glaring at them , intones , " You will believe me ! You will let us go ! " Having distracted the guards with this spectacle , the Doctor and Ace flee into the corridors of the castle . As they run , Ace sees a portrait of herself hanging on a stairwell wall . When she says she does not remember this happening , the Doctor tells her that it has not happened yet . Richard asks Peinforte what she will do when she gains control of the Nemesis , and she replies that first she will exact revenge on that " predictable little man " . She predicts that he will soon arrive , and tells Richard she knows the secret of the " nameless Doctor . " De Flores and his Nazis make their move for the Nemesis comet and see the unconscious policemen . He takes the bow case and places it on the comet , and within the Nemesis statue begins to glow . The Doctor and Ace arrive , and De Flores demands they hand over the arrow . The Doctor reveals that the bow and arrow give the validium metal critical mass . The Doctor confronts De Flores and asks if he has observed the advanced technology , which has been used to attack the policemen , and the power blackouts that have been occurring over the last few days . De Flores threatens to shoot Ace if they do not tell him where the arrow is , but at this moment a large spacecraft lands near the crash site . The doors open and from within emerge a troop of Cybermen . Part two . The Cyber - Leader recognises the Doctor , even though his appearance has changed , and tells the onlookers that the Cybermen had predicted his presence . The Nazis open fire on the Cybermen but their bullets are ineffective . The Cybermen open fire and drive the Nazis away . The Doctor says that this happened before , but before it was the Roundhead s and Lady Peinforte . Peinforte shoots one of the Cybermen with a bow and arrow and de Flores finds the arrows to be gold - tipped . Peinforte and Richard withdraw , allowing the Nazis and the Cybermen to fight it out , hoping to retrieve the Nemesis in the aftermath . In the confusion , the Doctor and Ace manage to seize the silver bow and return to the TARDIS . Peinforte sees this and tries to shoot them , but her arrow thuds into the TARDIS door just as it dematerialised . While Peinforte and Richard enter the town of Windsor , the Cybermen begin to cut the Nemesis statue free of the comet . The Doctor and Ace go back to Peinforte ' s house in 1638 . The body of the mathematician has gone , and the chess pieces have also been moved . The Doctor tells Ace that although the mathematician was a genius , he had needed a little help to get started . The Doctor picks up a piece of paper from the desk and throws it into the fireplace . The Doctor makes a further move on the chessboard , and they leave . Materialising back in the present day , the Doctor explains that validium was created on ancient Gallifrey by Omega and Rassilon as the ultimate defence . Some of it , however , left Gallifrey , and now they must stop Peinforte or anyone else reuniting the statue , the bow and the arrow . Using the bow to lead them , they proceed in the direction of the statue . In Windsor , Peinforte and Richard are confronted by two thugs , who think they are mugging social workers . The Doctor finds and questions them later ; they had been left semi - naked , dangling from a tree . As Richard is terrified by the sight of a bizarre creature , a llama , Peinforte tells him that if he does not help her retrieve the Nemesis , she will abandon him in this future time . He then sees that they are standing by a memorial statue . She tells him that it is his tomb , placed in the grounds of her own burial place . The arrow starts glowing and they realise that that is where the Cybermen have taken the Nemesis statue . As they scour the tomb for Nemesis , the Cybermen prepare to attack , but realising they are armed with gold arrows retreat . Opening up her grave , they see that it does not contain her bones . Much to her surprise , the Doctor orders Ace to destroy the Cybermen vehicle with Nitro - 9 explosive . De Flores strikes a deal with the Cyber - Leader to kill Peinforte and Richard in exchange for a share of control of Earth after its conquest . The Cybermen have no intention of honouring the deal , and plan to kill the Nazis after the death of Peinforte . The Doctor tells Ace that every time the Nemesis comet approached Earth in its 25 year orbit , it caused destruction : in 1913 , the eve of the First World War ; 1938 , Hitler annexed Austria ; 1963 Kennedy assassinated , and now it is 1988 . They use the tape deck scanner to try to find the Cyber - fleet . Opening up the grave fully , Peinforte gazes upon her own image shown on the Nemesis statue . However , De Flores and his man arrives with guns , and Richard has only one arrow left . In fear , he hands over the arrow to De Flores and drags Peinforte away , leaving the Nazis in control of Nemesis . De Flores believes he now has all three parts of the validium . He places the arrow in the statue ' s hands , and it becomes more animated . The Cybermen arrive and ask De Flores where the bow is . When he opens the case he sees that he does not have it at all . The Doctor sees a lizard emerge from hiding and realises the Cyber - fleet is shrouded . He makes an adjustment to the tape deck and reveals the entire fleet of Cyber - warships , thousands of them . . . Part three . The Doctor decides to activate the validium by taking the bow to the crypt . When Ace seems frightened , the Doctor tells her she can wait in the TARDIS , but she refuses and wants to accompany the Doctor . Meanwhile , De Flores realises he has overplayed his hand and tries to negotiate with the Cyber - Leader . The Cyber - Leader orders his lieutenant to kill De Flores , but he throws gold dust in the Leader ' s face and flees . As the Doctor and Ace arrive at the crypt , the jazz tape finishes playing and the Cybermen ' s communications begin working . The Doctor enters the crypt holding the bow , and , manoeuvreing past the Cybermen with Ace , places the bow in the statue ' s hands but snatches it away again . The statue awakens and begins to follow the bow . Going back to 1638 , the Doctor continues his chess game against his unknown opponent . Ace asks him who brought the validium to Earth in the first place , and what is really going on , but he remains silent . Taking a bag of gold coins , they leave . Peinforte begins to rant about all power being hers and her intent to retrieve the Nemesis . They come to the road and attempt to hitch a lift in a passing car . Richard stands with his thumb out , but no cars stop for them . Seeing this fail , Peinforte steps into the middle of the road . A large car stops , and an American woman offers to take them into Windsor . She tells them that she is in England discovering her roots . Revealing she is descended from the 17th century Remington family , Peinforte calls them thieves and swindlers . Mentioning a Dorothea Remington , the American woman recognises the name , and Peinforte knows that Dorothea died in 1621 from a slow poison . Meanwhile , the Doctor and Ace materialise inside the hangar containing the comet . Soon the Nemesis statue arrives , and the Doctor gives it the bow . The Nemesis speaks to Ace , telling her that it was fashioned by Peinforte into its current beautiful form , but that it has also had horrific forms in the past , and will again in the future . The Cybermen arrive , and Ace shoots one down using a gold coin and shoots it with a slingshot . The Cybermen pursue her , but she manages to elude them . The Doctor sets the trajectory of the rocket sled containing the Nemesis , headed for the Cyber - fleet . Ace becomes trapped on a gantry between two Cybermen and the Cyber - Leader , with only a single remaining gold coin . The Cybermen lift their guns to shoot her , but she fires the gold coin at the Cyber - Leader and ducks , causing the other two Cybermen to shoot each other instead . The Nemesis asks the Doctor if she must destroy the entire Cyber - fleet , to which he says that she must . She asks the Doctor whether she will be needed again , or whether she will have her freedom , but the Doctor hushes her . Ace arrives down from the gantry , but is surrounded by two more Cybermen . They demand that the Doctor hands the bow over to them , but the Doctor threatens to destroy the bow if they harm her . Placing it in front of the rocket sled engines , he grabs Ace . As the two Cybermen advance towards them , the engines fire , killing the two Cybermen . However , up on the gantry the Cyber - Leader plucks the gold coin from its chest unit . De Flores arrives and picks up the bow . He speaks to the Nemesis , but she remains silent . The Cyber - Leader raises his gun and shoots De Flores dead , and demands that the Doctor hands over the bow . At this point , Peinforte and Richard arrive . Demanding the bow for herself , she asks Ace who the Doctor is , and whether she knows where he came from . Ace says that nobody knows who the Doctor is , but Peinforte says that she does . When Ace asks how , she says the Nemesis told her . The Doctor asks what will happen if he gives her the bow , to which Peinforte replies his power will be hers , but his secrets remain his own . Appearing to concede defeat , the Doctor says he is surrendering , but not to Peinforte , rather to the Cybermen . Peinforte threatens to reveal his secrets , so he calls her bluff . She says that she will tell them of Gallifrey , of the Old Time , the time of Chaos . However , the Cyber - Leader says that the secrets of the Time Lords are of no interest of the Cybermen . The Cyber - Leader tells the Doctor to cancel the Nemesis ' s destructive capabilities . The Doctor asks the statue if she understands the Cyber - Leader ' s instructions , and she replies , " Perfectly " . The triumphant Cyber - Leader tells the Doctor to set the statue ' s course to rendezvous with the Cyber - fleet . He tells them that the Earth will become their new base planet , the New Mondas . As the Nemesis launches , Peinforte screams and throws herself into the rocket sled and merges with the Nemesis . The rocket sled takes off and heads out into space . It arrives in the midst of the Cyber - fleet and there is an enormous explosion , destroying all of the Cyber - warships . The Cyber - Leader asks how it is possible , and the Doctor replies that he merely asked if Nemesis had understood the instruction , but had not said anything about obeying them . The Cyber - Leader prepares to kill the Doctor , but Richard grabs the gold - tipped arrow from the TARDIS door and stabs it into the Cyber - Leader ' s chest unit , finally killing it . The Doctor and Ace return Richard to 1638 . There , Richard and a Stuart woman perform a concert for them . Ace asks the Doctor who he really is , but he just puts a finger to his lips and listens to the music .