Harry, Sarah, and the Doctor, interlinked via their hands, spiral through space and time amid the cosmos. They are taken to the Nerva Beacon space station. Sarah when asked by the Doctor if she doubted they would make it here, tells him that after the past few weeks, yes she did. Short of a molecular short circuit, the Time Rings are most reliable. They have arrived earlier than the TARDIS, which is drifting back through time to meet them here. Harry asks the Doctor if he doesn't want the Time Ring, if he could keep it. The Doctor tells him he can but when Harry moves to take it, the Time Ring has a bit of electric go through it and it vanishes. Harry asks the Doctor, "You knew that would happen, didn't you?" The Doctor opens a door and a dead man falls in, having died sitting against it. Harry deducts the man has been dead about a week or two. In a sterile environment, there is little decay and Harry can detect no injury. In the hallways where the windows are, the trio find a lot more bodies.
Warner, a Spanish looking communications technician reroutes a Pluto-Earth 1-5 spaceship, telling them that this station, Nerva Beacon, is under quarantine due to a plague. He transfers them to the Ganymede beacon. The man talking to him from the spaceship asks about his brother on Nerva -- a crew master Caldwell. Warner calls Commander Stevenson in the Crew Quarters and asks what he should tell the brother. Against citizen Kellman's advice, Stevenson tells Warner to lie. Earth Center told Stevenson to do this. Kellman asks how three men can keep doing the work of 50. Nerva is on a 30 year assignment in orbit near the remains of an asteroid in order to warn spaceships of the asteroid's presence. It is relatively new to this area of the solar system and is not on the charts yet. This is the end of the 25th century. Kellman leaves; leaving the two men there, Lester, an officer and Stevenson, to talk about him. Kellman locked himself up in his cabin at the first sign of the plague.
In Section Q, the Doctor, Harry, and Sarah find many more bodies which they have to step over. They were left here to die. Sarah tells the Doctor this is not "our ark" but the Doctor tells her it is. It is just at a different point in time -- thousands of years before the solar flares. The TARDIS might materialize in the forward control room if things were changed around in the 30th century. The trio fail to see a Cybermat creature in the hallway, moving through the bodies.
A long haired very alien faced Vogan tries to call Nerva and gets a brief, garbled message through before two others with shorter hair, fire guns at him, shooting him in the head and killing him.
Kellman walks into Warner who claims he heard a transmission from the planet. The rock came into the solar system 50 years ago, having been previously drifting in space between the systems, in the vacum. Kellman set up a transmit station down on the rock and tells Warner there is no life on the rock. He spent six months studying rocks from the planetoid. But the message started and some info from it is Day 3, Week 47. Kellman thinks it is a mistake to keep the control room operating but Warner tells him it is not his say. Kellman also warns that anyone going down to the planet Voga is in danger of spreading the disease. Warner insists if the Commander wants the control room open, it stays open. Kellman leaves.
Using the sonic screwdriver, The Doctor cuts out the rivets in a small square of a door and puts his arm through. He hits the switch but the door moves with his arm in it. Sarah and Harry cannot stop it (Sarah yelling and screaming, "Doctor!"). The two pass through and the door shuts with the Doctor's arm still stuck. Sarah gets the arm out and opens the door. While the Doctor thanks her, he stares needles into Harry and moves past him. Harry asks Sarah, "What have I done now?" Sarah can only nod.
Warner alerts Lester to alert Stevenson that the electronic register has alarmed him that someone is in the section that no one should be in. Lector does so and he and Stevenson arm themselves.
Vorus, on Voga, talks with his aide, Magrik, about an agent they are waiting word from. Vorus orders more Vogan men to bury the dead communication Vogan, shot earlier. Gold buys humans and their agent on the Nerva beacon. There is more gold on Voga then in the known galaxy. Magrik fears the Cybermen were monitoring their transmissions on the radio. Vorus tells him fear of Cybermen will be a thing of the past very soon.
A Cybermat attacks Warner from behind, biting his neck before he can throw it off.
Lester and Stevenson find the rivets in the door in the P Section have been removed. Stevenson figures a sonic vibrator could have done this.
Kellman goes to Warner and sees the lights looking like veins on his face. Kellman pulls the log tapes off the machine.
The Doctor, Sarah, and Harry enter the Control Room area but since the Time Ring had a safety margin, the trio have arrived before the TARDIS. Harry asks the Doctor if he is to believe that that old Police Box will appear out of nothing. Lester and Stevenson tell the trio to put their hands up. The Doctor explains they are travellers and introduces Harry, Sarah, and himself. Kellman opens the door to the radio area and tells them to look at Warner.
While Sarah and Harry put their hands down, the Doctor keeps his high up. Stevenson checks Warner and then stands back, unlatches his gun and is about to shoot Warner. The Doctor puts his hands down and checks Warner, "I can't allow it," he says of Stevenson's wanting to shoot Warner to contain the plague. He goes on to tell them his friend Harry is a medical doctor and "I'm a doctor of many things." Kellman insists Stevenson kill them since they have the plague also. The Doctor asks, "Who's the homicidal maniac?" The medical team on the Nerva Beacon died first. The Doctor doesn't believe this to be plague and Stevenson will allow the Doctor to examine Warner but they have to move him to the Crew Quarters.
Kellman moves to his cabin. He takes out a device to spy on the Doctor and Stevenson as the Doctor examines the room where Warner was attacked. The Doctor has seen scratches on the metal and on Warner which remind him of something he has seen before...he just can't remember where. Stevenson asks if it is important. "Everything's important!" The Doctor finds the taped log gone, convincing him even more this is not a disease.
Sarah finds Warner's pulse is up to 120 and he is burning up in the Crew Quarters. Harry commends Warner's strong constitution; Lester telling them he is as strong as an old boot. This is the 79th day of the plague; Earth isolated them rather than risk spreading an extra terrestrial disease back on Earth.
The Doctor asks about why they are here. Stevenson tells him to study Jupiter but the Doctor knows it has been studied extensively already. Stevenson tells him the new satellite -- now the 13th moon -- not on any charts it was first named New Phobos but changed to Voga, a planet the Doctor has heard of before. It is all coming back to the Doctor -- "Cybermen -- that's what we're up against -- Cybermen!" Stevenson thinks they died out centuries ago. The Doctor explains they vanished at the end of the Cyber Wars when they tried to attack Voga, "They're utterly ruthless, total machine creatures." The Doctor runs out.
Kellman send a message to a Cybership run by a black helmeted Cyberleader. The Cybership heads for the Beacon.
Harry tells an arriving Doctor that Warner has had it. The Doctor finds puncture marks on Warner's neck, "If only I had have been quicker -- I might have saved him." Matter beams can separate and reject alien poison. "I smell a rat," the Doctor says and leaves. Stevenson remarks, "You know I sometimes wonder if your friend is quite right in the head." Sarah tells him if the Doctor smells a rat, there is one to be found.
In Kellman's cabin, the Doctor finds a device for communicating and some gold. Kellman returns and the Doctor is forced to hide under the bed but Kellman realizes he is there. Kellman sets a device in the small closet on the wall, exits, and locks the door from the outside. The Doctor comes up out from under the bed and sees smoke start across the room. His shoes are electrified so he jumps up onto the bed and makes his way across the open closet doors to not touch the floor. Smoke gas rises into the room.
Harry, Lester, and Stevenson take Warner's body out. At first, they used the infra structure of the ark as a mortuary but then they had to leave the bodies where they dropped. As the men leave, Sarah finds a tape machine and begins playing tapes to find out more.
The Doctor avoids the smoke and the electrified floor and takes out the sonic screwdriver to start working on the locked door to free himself.
As Sarah listens to reports on radiation near Zerus, a Cybermat sneaks up behind her, over a tube, and launches itself at her. She is just getting up from the chair as it comes at her and she sees it. It attacks her neck and she cannot hold it off from biting her in the neck...
The Doctor finally breaks out of Kellman's cabin to hear Sarah's screams. He rushes to her and finds the Cybermat. Reaching into his long pocket, he pulls out some gold and kills the Cybermat with it. The glowing "disease" is already started on Sarah's neck and face. Harry, Lester, and Stevenson come running. The Doctor wants to send Sarah and Harry down to the asteroid Voga to save Sarah. He warns of other Cybermats around.
At the transmat, the Doctor finds that someone took the pentalion drive -- a saboteur -- Kellman, who is watching them on his small TV scanner. Kellman arms himself.
The Doctor substitutes the monosurger to the output while Harry waits on the transmat platform with Sarah, "Doctor, she can't last much longer." The Doctor works feverishly, "I know, Harry, I know!"
Lester and Stevenson break into Kellman's cabin and find him gone.
On Voga, Vorus also watches a scanner: his rocket Sky Striker. He tells Magrik that the Cybermen are on their way and that he has four hours to fix the bomb head to the rocket. Magrik will round up all the engineers to do so. He seems to have a cold of some kind, constantly blowing his nose.
The Doctor has to hold a wire in place to send Harry and Sarah down and the device blows in his face. He holds his face but when he sees that they have been transmatted down, he smiles.
Sarah recovers and tells Harry to stop babbling at her like some fog horn with that loud voice of his. He is just happy she is alive. He sees gold, moving past some rock overpass. Sarah doesn't think it is gold at first. Long haired alien Vogans come down some steps at them while Harry contemplates buying himself out of the Navy, finding a quiet practice in the country, and using a gold stethoscope. The aliens take the pair, roughly, to a gold cart transport on wheels.
On Nerva, Stevenson faces Kellman with his automatic machine gun drawn, Kellman in a similar position. Kellman starts to back into his cabin but Lester jumps him from behind and disarms him. They take him to the Doctor who needs that pentalion drive to get Sarah and Harry back. He also knows the Cybermen fear gold because as a non-corridible metal, it can suffocate the Cybermen when introduced to their breathing apparatus. The Doctor thinks Kellman is continuing to lie to gain time.
He's right -- the Cybermen alert the Cyberleader that it will be 16 minutes before they can dock.
Vorus, on Voga, questions Harry and Sarah, who think the aliens are mad because they believe Sarah and Harry took some of their gold. Vorus tells them the plan was for only four of the humans on Nerva to be alive. Harry and Sarah tell the truth: they arrived after the plague. Vorus isn't totally believing them and threatens them with suffering and asks if they understand him. They answer "yes." He tells them that it is said that humans are not without intelligence. He is the leader of the Guardians of the mines here. He wants to questions them further but for now has them put in confinement.
On a screen, Vorus talks to Councillor Tyrum, an older Vogan. Tyrum has sent a skimmer car or boat to get Vorus so they can meet.
On Nerva, Stevenson tells Kellman that as Space Service Commander he can immediately execute Kellman for having killed 47 of his crew. Kellman is not afraid but the Doctor has a trump card: he has filled the Cybermat with gold and sends it at Kellman. The Doctor smiles and tells Kellman that he has ten seconds to tell where that pentalion drive is. Kellman blithers that it is around his neck.
Harry and Sarah are confined to the caves near stalagtites and stalagmites. Their chains are solid gold. Sarah continues to insult Harry, who tells her he was just thinking that gold is soft and perhaps they can file through. They continue to argue a bit and Sarah tells him to stop blithering.
Tyrum tells Vorus that he knows there are humans in the gold mines. They have been seen. The Guardians care for the gold mines and the routes to the surface so they must have seen the humans. He thinks their being here is the contrivance of Vorus. He also knows that there was a murder in the mines. Vorus claims it was a matter of internal discipline. Vorus asks why they should remain underground due to a myth of fear of Cybermen or some struggle centuries ago with Cybermen. Tyrum no longer trusts Vorus or his guardians, thus he has sent the militia in to take over the mines. If there is any bloodshed, Tyrum tells it will be on Vorus's hands.
Harry hurts Sarah's poor ankle when he hits the chain around her ankle, "C'mon old girl," he says as he hits. He also insults her ankles, telling her they are thick as a cow's. Sarah wants to try to use the stalagmite as a lever.
A skimmer boat arrives with long haired aliens -- the militia -- who are fired upon by the Guardian Vogans.
Vorus orders Magrik to have the two humans killed immediately in case they are captured by the Militia and tell Tyrum all about his plans. Magrik sends a detachment to kill Sarah and Harry.
The transmat is working on Nerva but a new threat looms: a spaceship is on its way. Nothing from humans or Earth was due for 12 days.
Sarah frees Harry, who complains that he is maimed for life. They hear a skimmer docking car. They run but shorthaired Vogans follow them, meaning to kill. Harry and Sarah climb up rocks. They run some more, being fired upon but reach a dead end. Harry says, "Sorry old girl, we'll have to go back." They cannot as the Vogans are coming after them. The pair end up between two parties shooting at each other. This gives them the chance to run clear and down a tunnel but the Guardians chase and shoot at them some more.
Stevenson and the others on Nerva see a Cybership on the scanner but the two Earthmen don't know it is a Cybership. They notice missile tubes on the sides.
Harry and Sarah keep running. Harry helps Sarah down a rock incline but as they move on, they see a deep underground river. The Guardians arrive and point guns at them, ready to kill. Harry says, "This looks like the end, Sarah." Sarah murmurs that he never misses the obvious. Suddenly, the long haired militia surround them from higher up crevices and aim guns at the Guardians, who lay down their arm.
Tyrum and his aide Sheprah talk about what they have heard from Sarah and Harry. Vorus has locked himself and some men in the Guild Chamber. Tyrum thinks that even though Sheprah has told him with some men they can get Vorus and his men out, that they should wait. They should give Vorus, now considered a traitor who has committed treason, a chance to die in battle. The only way the people of this gold asteroid have survived is to stay in hiding and to regard all outsiders as hostile.
The Cybership docks on the Nerva Beacon's side. While Kellman smiles, the Doctor wants to prevent the Cybermen from getting in and he runs to the hatch. He can't lock it. The Cybermen enter into the hall as if in a funeral march or procession. The Doctor moves out of the way, behind a wall. Lester and Stevenson shoot at the Cybermen but the Cybermen return fire. They shoot sizzling light balls from their head ports on the foreheads. This makes Lester and Stevenson fall, seemingly dead. Out of view, the Doctor tries to sneak away but the Cyberleader comes around the corner and fires his head blasts at the Doctor. The Doctor falls onto his back. The Cyberleader shoots again! The Doctor is still. The Cyberleader says, "All resistance overcome -- the beacon is ours..." The Doctor looks dead...
Kellman arrives wondering if the Cybermen have killed the others but finds the Cybermen merely neutralized the trio. The three are needed for their plans. Kellman empties the Doctor's pockets to find out what he is and discovers a bag jelly babies which he empties onto the Doctor's stomach and then finds a rotten chewed apple core.
Sarah and Harry are brought to Tyrum, the Chief Councillor.
The Cyberleader on Nerva and Kellman plan: the mainshaft goes right to the core of Voga. Kellman put the receptors of the transmat as near to the shaft as possible. By now the three captives have recovered; the Doctor wondering what Kellman's cut is. The Cyberleader tells the Doctor this time Voga will be destroyed and "this time we shall not fail." He orders the Cybermen to bring in the explosives. Since pure gold is hostile to their functioning, Voga, the planet of gold must be blown up. For this reason Kellman was to "preserve" three animal organisms, the Cyber Leader tells them. The Doctor smiles at Stevenson, "Isn't it wonderful to feel needed, Commander?"
The civil war continues to rage on Voga. Sheprah relays a message to Vorus's men to tell Vorus of a cease fire.
Kellman pleads how necessary he is to the Cybermen and that he has already done much valuable work for them. For which, the Cyberleader tells him, he has been rewarded. Kellman wants to go down to check on the transmat alignment. The Cyberleader lets him but warns him that once the detonator cycle commences, it cannot be stopped.
Sarah and Harry talk to Tyrum of Vorus, trying to figure out why Vorus would kill them since they only saw him all of ten minutes. Tyrum tells them the city they are in was once a survival shelter during the war with the Cybermen. Sarah admits she has heard of the Cybermen. Tyrum feels they must go to Vorus.
The Doctor, on Nerva, tells the Cyberleader that everything is of interest to him. He wonders what the Cyberleader's plans are since, "You've no home planet, no influence, nothing. You're just a pathetic bunch of tin soldiers skulking about the galaxy in an ancient spaceship." The Doctor verbally spars with the Cyberleader, telling him that the victory of human ingenuity prevailed during the Cyberwars when the Cybermen were nearly wiped out. Humans created the glitter gun which put an end to the Cybermen's campaign of terror. No one has any use for Cybermen now, except as the Doctor says, "As a gold plated stands used as hat stands." Lester sees the Doctor has rilied the Cyberleader up and indeed the tin man looks upset, talking of a second campaign and how he has enough parts on his ship to build a new Cyberman army. The Doctor tells him that the trouble with Cybermen is that they have hydraulic muscles to go with their hydraulic brains. The Cybermen gets even angrier and grabs the Doctor's shoulders and puts pressure on him. He throws the Doctor but the Doctor uses this as a chance to grab one of the Cyber bombs. He wants the Cyberleader to tell him some information about Kellman. As the Cyberleader explains that Kellman will be given this part of the solar system to rule, he secretly sends a recall alarm to another Cyberman, who begins to return. The Doctor didn't think Kellman's ambitions lay in the area of power to rule. He is grabbed from behind by the other Cyberman.
Kellman transmated down, goes to see Vorus but arriving in the middle of the Civil War, he is taken by Sheprah. Kellman yells that they are all in danger now.
Cyberbombs are fitted around the Doctor, Stevenson, and Lester, tied with the bombs on their backs. Belts are tied in the front with a mechanism which cannot be removed. If it is or if it is tampered with, it will detonate the bomb on the back. These Cyberbombs, which were banned by the Armageddon Convention, the Doctor reminds the Cyberleader, have enough power so that three of them planted in the core of Voga will destroy it. The Cyberleader tells the Doctor that the Cybermen do no conform to a theory of morality in war. The Doctor makes fun of the Cyberleader's word fragmitize, "I suppose you can't expect decent English from a machine." The bombs are primed and the removal of the harness attachments will cause an explosion. The Cyberleader tells the three that they have 14 minutes to plant the bombs and to reach the transmat beam. Their progress will be followed by radar. If they deviate from the told course, the bombs will be detonated. The Doctor says, "Thank you." A Cyberman pushes the Doctor toward the transmat. The Doctor warns, "Careful, careful, I might explode!"
The Doctor and the first Cyberman arrive, the Doctor playing with a yo-yo from his pocket. Lester and Stevenson arrive with the other Cyberman. Vogans arrive and start firing on the metal monsters, giving the Doctor, Stevenson, and Lester time to get away from them and into the rocks. About seven Vogans are shot down dead; one reaches for his gun on the ground and another is shot while on the ground. The Doctor and Lester concur that the Cyberleader lied about giving them time to get away before the explosion.
The Cyberleader tells his Cybermen on Nerva that Kellman is of no further use to them. His part is at an end.
Kellman is brought to Tyrum. He tells the older alien that he and Vorus lured the Cybermen here into a trap. Vorus has the Sky Striker rocket aimed at the Beacon to destroy the Cybermen. Sheprah reports the Cybermen are already here.
High up on cliffsides, the Vogans attack the Cybermen with gunfire. Most of the Vogans are shot dead by the Cybermen's head sparks. Only about two Vogans escape, one injured and helped out by the other.
The Doctor thinks his idea is better than Lester's, "I think my idea's better." Lester asks, "What is your idea?"
"I don't know yet," the Doctor responds, "That's the trouble with ideas -- they only come a bit at a time."
Tyrum is trying to get the attention of the Guardians near the Guild where Vorus hides out. They fire upon him. Harry sends Sarah to transmat up to Nerva to warn the Doctor about the rocket while Harry plans to stay here and see what he can do about the rocket from being fired. "Take care," Sarah tells him. Harry sees her off, "You too."
Vorus calls off his guards. Tyrum explains about the Cybermen attacking. Kellman tells Vorus he couldn't delay them any longer. No Cyberman was supposed to come down to Voga. Harry relays that Sarah went back to Nerva. Kellman thinks that if "that girl reaches the beacon and starts blabbing about the rocket, the Cybermen will explode their bombs."
Sarah sneaks behind the Cybermen. She moves along a ridge behind them as they fire on more Vogans. Sarah gets to a sea skimmer boat and takes off on it on the other side across the river. Two Vogans escape the attack of the Cybermen. More die. The timer on the Cybermen's countdown button clicks away.
Sarah gets to the other side of the river and transmats herself up to Nerva where she hears the Cyberleader tell the Cybermen there that the three humans can no longer be detected separately and that in 17 minutes the three will get to the central chamber unaware when the countdown enters the red zone, the bombs will be detonated. The gold is causing the radar disruption as the three go deeper and deeper into Voga.
Vorus tells the others that his Sky Striker was planned for two years but Magrik reports a delay in the bomb head. Tyrum chides Kellman as a traitor, murderer, and selfish killer. Harry asks if there is another way to the central shaft. Tyrum recalls that when the shaft was widened a cross shaft was dug for ventilation. He, Harry, and Kellman go to have a look.
The Doctor, Stevenson, and Lester climb. Stevenson says he is too old for this sort of thing. The Doctor tells him to rest for a moment. The Doctor and Lester go on for a bit, the Doctor noticing that the deeper they go, the heavier the concentration of gold is. Lester asks about the Doctor's plan. The Doctor thinks with the disruption of the radar, they can slip around and "take the Cybermen from behind." The Doctor see the Commander and asks if he is all right.
At the adjoining area, Harry sends their rock expert Kellman through the shaft first to check it.
The Cybermen kill more Vogans.
The Commander tells the Doctor he is winded again. The Doctor tells him to sit down a moment. They are very near the center now. The Doctor moves upward to check the walls -- and finds solid gold.
Kellman and Harry crawl to the end of their horizontal shaft and find it blocked by rocks. Harry pushes the rocks to see if he can dig through. The rocks start to fall. On the other side of it, the Doctor yells a warning to Lester and Stevenson but is rained on by rocks himself.
Kellman saves Harry's life by pulling Harry out of the way from the rain of boulders. Kellman falls and gets a big boulder on his chest, killing him.
The Doctor rolls down the wall side hill and a few rocks hit him in the stomach. He lies on the ground unconscious.
Harry checks Kellman and closes his eyes, realizing the man is dead. Harry goes to the new opening he just created and goes through to find the Doctor on his back. Harry checks the Doctor -- alive. He then sees the lock around the Doctor's body and starts to remove it, "Not to worry -- I'll soon have you out of this thing." He begins to turn the turnstile on the belt harness...
Lester stops Harry before Harry can remove the harness. The Doctor recovers and opens his eyes. He asks Harry if he is the one who caused the explosion and when Harry tells him he must have, the Doctor asks if Harry was trying to remove the harness. Harry tells him he was. The Doctor looks at Lester and smiles, then leans back, but leans forward again, laughing wildly. He cups his hands to his mouth and yells out into the echoes of the caves, "Harry Sullivan is an imbecile!!!" Harry looks at Lester and embarrassed, frowns.
On the Beacon, Sarah overhears the Cyberleader planning to destroy Voga.
Harry is quickly trying to explain what is happening to the Doctor, "I can see you're not following me." The Doctor says, "I'm not following you." Harry continues but Lester reminds them they only have nine minutes. Stevenson will take his bomb toward the center to draw off the Cybermen's radar while the other three will attack the Cybermen from the rear.
Vorus is told by Tyrum that if they survive this, Vorus will be put on trial for treason. Sheprah arrives, wounded, and tells them the Vogans will not attack the Cybermen, they have had too many losses. They need to time to regroup. Tyrum offers to speak to the troops.
Harry and the Doctor jump off a ridge over the Cybermen and try to stuff gold into the chest plates of the two Cybermen. The struggle goes badly for Harry and the Doctor who must run for it. Lester sees his chance and jumps down, lands on his hands and knees. He opens the lock on his harness and blows himself up, downing and killing the two Cybermen in the process. The Doctor sees the bomb the two Cybermen had -- it is still ticking.
On the Beacon, the Cyberleader gets a signal that something is amiss. He tries to detonate the bomb manually. Sarah runs in and tries to stop this but is thrown from him to the other Cybermen who toss her to the floor. The Cybermen detonate but the bomb does not go off.
The Doctor has stopped it and using gold, is able to open his harness, "Well, I'm impressed."
Sarah is tied up and put into a chair. She tells the Cyberleader of the Vogan rocket and how Kellman betrayed the Cybermen. The Cyberleader insists that one way or the other Voga will be destroyed.
Tyrum greets the Doctor in his chambers, grateful to him but calling him human. The Doctor says, "Oh please, don't call me human, just Doctor will do nicely." He asks Tyrum for 15 minutes since he has a young friend, Sarah Jane, still on the Beacon. She risked her life to warn him and the least he can do is risk his to try to save her. He asks for a bag of gold dust. The Doctor leaves, telling Harry to find the Commander. Vorus is impatient but the Doctor is given the time and transmats up to the Beacon.
The Cyberleader will send the Beacon, carrying large Cyberbombs, into Voga's center. He tells Sarah she will enjoy a closer view than they. After he leaves, Sarah tries to get free and cries. The Doctor appears and whistles a signal. Sarah whistles back and he whistles back again. He rushes to her and unties her, asking if she has seen any sign of the TARDIS. "The TARDIS?" She asks, explaining the situation to him. The Doctor is stopped by Sarah, "Doctor, it's good to see you." They get the control box and the Cybermat.
The Cybermen are loading bombs onto the nose cone of the Beacon.
On Voga, Tyrum stops Vorus from firing the rocket at the Beacon. Vorus claims he will still be the people's liberator. Harry and Stevenson return.
In the Beacon Crew Quarters, the Doctor fills the Cybermat with gold dust. Sarah doubts it will attack the Cybermen but the Doctor says, "Just you wait and see." The Cybermen find Sarah has been released. The Leader tells the others to locate and destroy all animal organisms and to engage the hyperdrive. A Cyberman comes into the crew quarters but the Doctor makes the Cybermat attack and kill it. It falls but the station shakes and tilts. Sarah runs out into the hallway. The Doctor starts to follow but stops and ponders over the dead Cyberman, "Out, out, dusty death." Sarah comes back and pulls him, annoyingly screeching, "Doc--Tahhh!" He turns, "What? Yes." She pulls him by the arm into the hallway.
Vorus sees the Beacon coming at Voga and goes to fire the Sky Striker rocket. Harry fights him away from the controls but is hit down by Vorus. Commander Stevenson grabs Vorus away from the controls. Magrik moves to fire but Tyrum shoots and kills him. Vorus hits the Commander down with a staff and moves to fire. Tyrum shoots Vorus dead too but Vorus dies, falling onto the firing button and shooting the rocket, "His glory," off.
The Doctor and Sarah's attempt to get into the control room fails -- or rather they get into it but only succeed in killing one Cyberman. The Leader grabs the Doctor and throttles him from behind while the other Cyberman grabs Sarah off her feet and down again, doing the same. The Doctor admits surrender. The Leader makes the Doctor tie Sarah up -- the two are tied back to back. The Cybermen leave, the Leader telling the Doctor they are leaving. "Bye Bye," the Doctor smiles.
The Doctor mumbles something about learning gromits from Harry Houdini and how to tie knots he can get out of. Sarah thinks the Doctor must have got it wrong but he unties both of them. The Doctor calls Stevenson and tells him to tell Vorus to aim the Vogan rocket at the Cybership. Stevenson tells him Vorus is dead and none of them know how to operate the controls. The Doctor says, "Just let me think." Stevenson asks, "Let you what?" Harry responds, "Let him think." The Doctor then tells the Commander what the controls are including the stabilizer controls. The Commander follows his instructions and the rocket passes over the Beacon as Sarah and the Doctor watch. The Doctor says something in Latin, "I think it missed." Sarah says, "But we're still heading for the biggest bang in history." The Doctor thinks he can fix that but finds the Cybermen have locked the gyro controls, therefore they are still heading for the biggest bang in history. Stevenson sends the Vogan rocket into the Cybership and it blows apart into a fireball.
But the Beacon is still heading at Voga. Harry tells the Commander to remind the Doctor, "He does have these absent minded moments." They call but get Sarah who tells them she and the Doctor are very much aware that the Beacon is still on a collision course. Harry tells her to do something, old girl. She explains. The Doctor sabotages the Cybermen sabotage and hooks up a tube to the wall and to the console. The station moves and vibrates, passing over the surface of the asteroid at a fantastic rate. It might break in half before it crashes but finally, it spirals past the planetoid and goes off into space. The Doctor informs Sarah it will settle in nicely now. Sarah, dizzy, nearly falls, "Oh good." The TARDIS appears. The Doctor goes inside to stabilize the drift compensators, "We don't want it slipping through our fingers." As he goes in, Harry appears via transmat, seeing that Old Faithful -- the TARDIS -- turned up after all. The Doctor comes out and urges the two of them into the TARDIS. Sarah comments, "Oh, it's all go, isn't it?" The Doctor explains that he left the Brigadier a space time telegraph and told him not to use it unless he has a real emergency on his hands. Sarah drops her shoulders, "And he's used it?" He has. The Doctor goes into the TARDIS. Harry asks if they should stop and say cheerio to the Commander. Sarah and the Doctor urge him on in. Sarah yells, "Don't argue." The TARDIS vanishes.
|Source: Charles Mento
The Doctor claims that Jupiter’s new moon brings the total to thirteen, but in the real world, Jupiter is currently known to have many more than thirteen satellites. The reason for the discrepancy is revealed in the novel To the Slaughter