The TARDIS receives a distress signal that appears to emanate from the South Pole. Materialising in the snowy wastes, the Doctor and Donna make their way down to a group of men who have excavated something alien from the snow. They say that the creature has been taken back to their base to be thawed out. The Doctor and Donna take a ride with the men in their Snow-Cat but when they arrive at the base mayhem has broken out. A huge alien creature is rampaging round the base, impervious to bullets. It has destroyed the laboratory where it was thawed and is murdering everyone it come s across. The Doctor sets off in pursuit, leaving Donna in the wreckage of the tunnels with some of the survivors. Out on the snow, someone steals the TARDIS. Two hours later the Doctor returns, crawling through a tunnel under the floor. He tells Donna to join him but she does not want to leave the rest of the men to the monster so he passes her a device that he says will help in the fight…
In the base, the Doctor is creating a sonic field generator to fight the beast when a door opens in the air in front of him and he sees himself step out, holding up a long metallic rod.
On the semi-mythical Planet 1 the sole human occupant is expecting visitors. He is Sebastiene and he lives in an almost impossibly advanced technological world where he lives in a Ruritanian chateau that stretches from horizon to horizon. The technology works on a molecular level so that he or his legions of robot servants can summon almost anything out of the air. For the time being he is indulging a fantasy of life in the Europe of the eighteenth century. He has dressed his robots in the wigs and costumes of his chosen period and is awaiting the arrival of twelve shuttle ships to drop down to a landing pad within the chateau. From each shuttle comes a human (or near-human) occupant, and a giant insect. They are transported to Sebastiene s conference room where he greets them. He tells them that he knows that they are the members of the Endangered Dangerous Species Society, who track down and kill exotic dangerous creatures, thereby eliminating many rare breeds. Despite their denials of any knowledge of such a society he tells them that he has brought them to his planet to hunt down the last surviving Time Lord, the Doctor.
Some of the Society doubt the existence of the Doctor, whereas Sebastiene claims that every child in the galaxy has heard of him. He tells them that if they agree to his challenge they will be dispersed around Planet 1 into zones especially designed to replicate their own chosen hunting environments. The Doctor will be transmatted into one of these zones. If he is tracked and killed by this hunter the rewards will be for him alone and the remainder of the Society will receive considerable compensation and be returned home. If a hunter loses the Doctor then he will become Sebastiene’s prey and the Doctor will be randomly transmatted to another zone. Hearing these rules causes Brutus the augmented Simian to leave in disgust saying he wants no part of it, but as he reaches the door Sebastiene vapourises him and the remainder agree to the conditions in silence.
They wonder how Sebastiene will lure the Doctor to Planet 1 but he replies that the=2 0Doctor is already there. He presses a button and the TARDIS materialises in front of them and the Doctor steps out, winking. Sebastiene tells them that this is not the real Doctor but a man called Baris. He lived on Proxima and was the Doctor’s biggest fan, trawling the galaxy for news of his hero. Sebastiene has brought him to the planet and given him a genetic makeover, including an extra heart and Time Lord DNA so that, physically at least, Baris is the Doctor. Baris claims that he has kidnapped Donna (she is shown on a screen, sleeping in a darkened room) and stolen the TARDIS. If the Doctor wants either of them back Baris left an open Transmat device that will bring him to Planet 1.
The hunters are transmatted to their zones and Sebastiene details Baris to keep the Doctor under constant surveillance. A robot announces that the Doctor has been tracked to the Oroobian Jungle zone where a hunter called Lord Percy is waiting.
The Doctor is sure that he should be able to think of a better way of escaping than merely running. He forces himself to run through the dense jungle, the only thought in his mind is to find Donna. Pursued by beast men, he tumbles down an incline into a clearing where Lord Percy is waiting. Collapsing to his knees he watches as the hunter raises his rifle. There is a shimmer of light and=2 0the Doctor disappears. In the control room Baris shrieks that the Doctor has gone and dismisses the air-screen in front of him. Sebastiene is sure that the Doctor has somehow used the transmat. The Supervisor robot says that this is impossible without breaching the Intelligent Molecular Technology (IMT) security protocols. Sebastiene immediately orders that the IMT be shut down until the methods that the Doctor used are discovered. The whole planet will shift to alternative technology and an underground monorail network and an army of robot maintenance crews are brought online. Baris wonders if the Doctor has an accomplice in the chateau, or if someone in the chateau is not who they say they are. Sebastiene denies the possibility and says that someone pressed shuffle on the transmat, sending the Doctor to the next zone. He leaves the control room, putting Baris in charge.
Baris is escorted to his room by Sebastiene’s Butler robot who takes the opportunity to express its dislike and distrust of the Doctor lookalike. It says it will be watching him and if he makes a wrong move it will, literally, crush him.
The Doctor finds himself in a desert. He cannot work out why the hunter was trying to kill him though he feels that he ought to know and be able to remember what is happening to him.
The next morning sees Baris back in the control room. The Supervisor robot is also making threats to Baris now but he is less alarmed and more amused by these now. All across the planet long-disused systems spring to life to replace the IMT. Factories, silos and monorail systems begin to function once more. Millions of robots are taken out of storage to raise communication masts and start up powerful fusion motors. Only the hunters in their hunting zones are unaware of the planet’s changeover.
Inside the Chateau the Doctor goes on the offensive and sneaks out of his bedroom. Reflecting on Sebastiene’s error he also thinks about Baris’s fatal mistake. Instead of merely sending the Doctor to the Chateau from the Snowcap Base he had started to gloat. He had wasted time explaining The Plan, and about Sebastiene and the hunters. The Doctor’s first reaction was surprise that he had so many fans in the universe, including one as avid as Baris.
In the control room the Doctor finds a new set of Virtual Reality interfaces, operated by gloves and goggles, and dozens of robots standing in silence. He thinks that rescuing Baris from the hunter was easy, simply by pressing the shuffle on the transmat he sent him to the next zone. The hard parts were making it look like somebody else had20done it and getting Sebastiene to switch off the IMT. Using the VR interface he works out a way of getting Baris out of the next zone. Elsewhere, the Supervisor tells Sebastiene that Baris is using the computers in secret and that he could have been the one who saved he Doctor but Sebastiene still refuses to believe that Baris had the knowledge to use the transmat protocols and obliterate any traces. However, he concedes that it can’t hurt to question him.
The Doctor has no sooner sneaked back to bed than the Butler crashes in and drags him off to Sebastiene who is taking tea in a formal garden. There, the master of Planet 1 suggests that logic suggests that the Doctor is Baris and Baris is the Doctor. Just as quickly he dismisses this thought as impossible and takes the Doctor to see his pride and joy. This is a huge trophy room where every dangerous predator in the galaxy that Sebastiene has killed is on display. The latest addition is the corpse of Lord Percy. Abruptly changing the subject back again, Sebastiene tells the Doctor that he finds it impossible to take things at face value and must check whether he is the real Baris or the Doctor. The Doctor is strapped to a couch and subjected to a two hour investigation that checks every aspect of his being, both physical and psychological. At the end of a terrible ordeal the Doctor hears Sebastiene tell him that he is now sure that he is Ba ris and therefore the only person on the planet that he can trust. He wants Baris to keep an eye on the Doctor and to try to become him.
Donna finds herself in an Exquisite Traveller Hotel in Bracknell. She does not know how she got there and has been waiting for three days after the Doctor apparently left a note telling her to stay where she was. Although the hotel gives the impression that it is full of guests (cars in the car park, noises from other rooms, and just-finished meals in the restaurant) she never meets anyone apart from the bland receptionist, Sadie. After three days she determines to leave and sets out into the endless rain but after walking for miles round deserted roads, with the sound of traffic always around the next corner, she ends up back at the hotel.
The Semblance of Draxyx digs in and waits in the desert for the Doctor. There are only two other life forms in the desert, Suckweed and the crocodile-like Soresox. The Semblance, ensconced within an armoured carapace sees the Doctor passing and moves to kill him. To his horror he finds himself trapped in Suckweed and under attack from a Soresox. The Doctor passes by all three of these camouflaged entities, oblivious to the deadly battle going on between them. The Semblance remembers that its vegetable and animal adversaries are Sebastiene’s robots, which only increases his worries.
The Supervisor tells Sebastiene that the Doctor has apparently tricked the robots into thinking that the Semblance was their primary target. Neither of them can fathom how the Doctor did this, though the Supervisor suspects Baris. After being dismissed from the control room the Supervisor begins a massive trawl through the data fields and reports to the butler that he has incontrovertible evidence that Baris transmatted the doctor out of the jungle. The Butler carries the Doctor from his bed and takes him to the Trophy Room where the Supervisor presents his evidence. The Supervisor shows Sebastiene the trail that the instruction to transmat the Doctor took, tracing it back through the planet’s intensely complex systems until its origin at the air-screen Baris was using. Unfortunately, the screen registration now shows that the screen used was the Supervisor’s. Sebastiene immediately sets his machinery in process to have the Supervisor scrapped. Sebastiene tells Baris that he is sure the Doctor has some over-arching plan and that he is sure he is about to work it out. Baris (or the Doctor) asks if he thinks it is staring him in the face, and stares him in the face. Sebastiene says he has a sure way of getting the answer he needs, but he must go away for a while. He tells the man he thinks is Baris that the Doctor is in the Beriagrad Zone but Baris’s access codes have been voide d and he needs the Butler to log him in.
The Doctor, or rather Baris who thinks he is the Doctor, finds himself in a new landscape: a war-torn alien city in the grip of a terrible winter. He stumbles through the frozen rubble, desperate to find Donna. Commissar Weimark is the Western Mark’s chief sniper and perfectly at home in the ruins of Beriagrad. He occasionally allows himself to think that the men he has with him are real troops, not Sebastiene’s authentic facsimiles.
When Weimark tracks Baris down he shoots twice at him from long range, but misses narrowly both times. Deciding to finish him from close range he pursues him to a crater but just as he is set to pull the trigger the ground opens up and Baris plunges down a hole. In the command room the Doctor has had to give up on his subtle devices for rescuing his hapless fan and simply open a door into the underground network. Klaxons sound and the Butler robot throws him from his workstation while the Doctor protests his innocence. Baris finds himself immersed in water that pours down through a trapdoor and deposits him in a Monorail station.
The Doctor finds himself staring down the barrels of a number of guns held by robots. The Doctor merely laughs and tells them that the y are falling for The Doctor Trap, which causes them to hesitate uncertainly. The Doctor explains that Sebastiene warned him about the Doctor Trap which basically involves the Doctor being caught and killed. He argues to the confused robots that this is when the trap will be sprung. This is why he keeps stopping him from dying. The key to the plan, he tells them, is that the man they are watching being hunted down is not the Doctor.
In the hotel Donna hears a car race into the car park. A handsome young man is pursued by three hotel porters who bundle him into the hotel. Donna sets out to find him and tracks him down to a room in the furthest wing of the hotel. She introduces herself as Donna Noble and he tells her he is a prisoner. Over a cup of tea he tells her his name is Sebastiene. He fills her in on Planet 1 and how he came there from Earth in 1973. Back then he was just a science student working in a Cambridge laboratory on a meteorite. Suddenly it zapped him to the planet. He was alone, but thought-wave receivers began to read his mind and provide him with whatever he wanted. He guessed that the technology belonged to a long-dead civilization. He soon came to grips with the planet’s potential and began to use the IMT to re-create both it and himself. Unfortunately, he says, someone else has come to the planet and taken it over, and this someone else also calls himself Sebasti ene. He says that he sent the distress signal that called the Doctor in but is afraid that the new Sebastiene has fooled the Doctor into thinking that he is the real master of the planet. Only the Doctor can rescue them from their prison, he adds.
Baris escapes from the station by clinging onto the outside of a high speed monorail train, shortly before Weimark and a group of soldiers drop into the station in pursuit. When the train carrying Baris arrives at another station further down the line he drops off in exhaustion. He sleeps on a metal bench but when he wakes up the train has gone and others that pass through do so at a speed too great for him to catch onto. By now he is starting to find a second set of memories in his mind. He thinks he must be the Doctor but someone wants him to think that he lived most of his life anonymously on Proxima. Just then, another train arrives and stops in front of him. Its doors open and the smell of cooked food escapes. He leaps aboard.
The Butler robot communicates with Sebastiene via a television screen and is surprised to find that his master believes in the Doctor Trap and is intent on discovering from Donna how it works.
Sebastiene is locked in a room and severely beaten. Donna waits outside the door until he emerges and bathes his wounds. This process is repeated regularly. He says that the other Sebastiene is transmatting into the hotel with his friends and performing the beatings. He claims that he doesn’t know why but together they conclude that it must mean that the other Sebastiene is trying to find the Doctor. The beatings grow worse and Donna fears for her new friend’s life. She grows more worried and finds that she is growing closer to the wounded man. He tells her that the Doctor is loose on Planet 1. Then he says that the beatings are to find out about something called The Doctor Trap and asks Donna if she knows what it is. Immediately Donna becomes angry. She tells Sebastiene that she knows exactly what the Doctor Trap is, it is a phrase that the Doctor has told her means she must beware of anyone who utters it. Sebastiene changes his demeanour, telling Donna that she will spend the rest of her life there and stalks off into the rain, saying that he will send someone to her soon.
The Doctor is dragged from his bed by the Butler and taken to the Trophy Room. This time Sebastiene shows him a screen. On it they can see Donna in her room. Sebastiene tells him that her air supply has been cut off and that she is being slowly asphyxiated. She will die unless the Doctor tells Sebastiene who he really is. He confesses immediately that he is the Doctor. However, this makes Sebastiene think that he is talking to Baris. He reasons that the Doctor stole the hypnotizing device from Baris in the Snowcap base and convinced him that he was the real Doctor so that he could help the Doctor evade the hunters in the Zones. When the Doctor grows anxious watching Donna die he asks Sebastiene to kill him so that he can regenerate to prove his point. Sebastiene replies that if he is the real Doctor he has no need of Donna and can let her die, but if the man in front of him is Baris he still needs Donna as a lure for the Doctor. This time the Doctor says he is Baris and Sebastiene smiles and re-oxygenates Donna’s room. He tells the Doctor that he is sending him into the hotel in the prison zone to meet Donna.
Later, Sebastiene explains to his robots that Donna will think she is talking to the real Doctor and reveal what she knows of the Doctor Trap. He thinks that the real Doctor will leave the monorail network and make his way to the prison zone from which escape is impossible. Really, he says, it doesn’t matter which man is the Doctor, because eventually they will both be caught. He then tells the Butler to inform the hunters that all of them are being moved to the prison, too. He prepares an atmosphere craft for himself and states that he is also going on the attack.
The Doctor arrives in the lobby of the Exquisite Traveller and notes the aural conditioning units, pheromones and replica human Sadie. He immediately switches her off. Making his way upstairs he finds Donna smashing her way into the hotel rooms with an umbrella, just to prove that they are empty. Even though Donna doubts that it is really him she follows him out of the hotel into the rain. The Doctor fills her in on the details of Sebastiene, Baris and the lure to get them to Planet 1. The part that angers him is that Baris had managed to get hold of a key to the TARDIS. Stopping abruptly by the road that leads to nowhere he opens a patch of ground to reveal a big red button. He presses it and the road slides apart to reveal silver steps that run down to an underground monorail station. They descend to the platform as a train rushes in and stops. Baris steps out and tells Donna that he has come to rescue her, much to the Doctor’s dismay. Baris claims to Donna that he is the real Doctor, so the Doctor tells her he is actually Baris, but more for Sebastiene’s benefit (he knows all of their actions are being monitored). Donna says her woman’s instinct is telling her that this is true and that the real Doctor is the fake.
Sebastiene literally punches the air with delight as he locks down the prison zone with his prisoners inside.20As his robots celebrate, only one is concerned. This one has noticed that another train is due to arrive in the station imminently and there will be a huge collision. The robot tells Sebastiene that the train went rogue forty six hours earlier in the Beriagrad Zone on the other side of the planet. Sebastiene’s confidence crumbles as he wonders how the Doctor, or anyone, could have such foresight, or the ability to hide a train from him for so long.
Vibrations in the station tell the trio that danger is approaching. They run up the steps and out into the open air. Baris aims for the hotel but the Doctor orders them all to lie down. Donna dumps Baris into the mud as a terrific underground explosion hits, burying them in soil. When Donna emerges she sees that most of the hotel has gone. The real Doctor helps Donna to dig Baris out of the ground while informing her that he saw Weimark’s train go off the map two days earlier, even though nobody else did. He says that Weimark will kill all of them, just to make sure he gets the right man. They carry Baris into the remains of the hotel to hide. Unknown to any of them, including Sebastiene, the hunters who are arriving in the prison zone have all been given new orders.
Weimark and two robot soldiers crawl from the train wreck. They make their way to what is left of the hotel and start to search the rooms. Upstairs in room 304 the Doctor and Donna have laid Baris on a bed. The Doctor is still filling Donna in on what he thinks has been happening. He has come to the conclusion that Baris allowed the Doctor to swap places with him in the Snowcap Base. Being the Doctor’s number one fan meant that Baris didn’t want the Doctor to be captured or killed. Instead of gloating, as the Doctor thought at the time, he was providing him with the opportunity to hypnotise him. More than that, the gloating was to make the Doctor think that Baris was the bad guy so that he wouldn’t feel remorse at sending him into the hunting zones.
When Baris wakes up, he seems to know his true identity at last. He says that he knew the Doctor would rescue him but when the Doctor says Baris made it easy by leaving overrides in the computer to help him Baris is puzzled and claims that he did no such thing. The Doctor now knows that there is someone else running the game.
Weimark reaches the corridor where the others are hiding. They make their way down the doors, kicking them in one after another. Baris tries to buy them time by running into the corridor while the Doctor drags Donna through the bathroom door. Just as one of Weimark’s soldiers is about to shoot, his head explodes. Weimark realises that someone else is using miniature missiles. As he dodges a second missile he sees Baris escaping round the corner. Baris runs down the stairs and leaps from a first floor window. Before he is smashed to a pulp on the bricks below an energy field lowers him to the ground. Sebastiene asks if he liked the tiny missiles. Suddenly Weimark leans from a first floor window. He shoots Sebastiene in the chest and claims victory. Sebastiene launches a volley of missiles that destroy the hotel.
The door from the bathroom has led the Doctor and Donna back to the Snowcap Base where they first landed. The Doctor has worked out that Sebastiene fooled him into thinking he was on Earth when they were on Planet 1 all along. As they drop down into the base another hunter, Colonel Sty of the Bolken Context, shoots at them three times and inexplicably misses. Before he can set off after them he is killed by another hunter, Zzorg Zero. Donna starts to descend the metal ladder into the base but triggers an energy net set to trap her and falls to the floor.
Inside the Snowcap Base everything is in silence. The Doctor knows that the surviving members of the Endangered Dangerous Species Society must be somewhere about, in hiding, so he shouts a warning to them. He uses his screwdriver to drop the lid of the base into place=2 0above his head and in so doing chops the feet off Zzorg Zero. Then he uses the screwdriver to switch off the sonic field that was keeping the rampaging beast within the base in check. Panic sweeps through the hunters inside the base. Two flee straight into each other’s blades and die. Three more run for the lower levels where the beast catches and kills them. Only one hunter hides in the shadows, waiting. The Doctor finds Donna and hauls her to her feet. They make their way through silent tunnels until they reach the remains of the laboratory.
The night passes slowly. Dona recounts Sebastiene’s story that he was from Earth in 1973. The Doctor concedes that it is possible but surmises that even Sebastiene might have forgotten his true origins. What the Doctor is sure of is that someone else is running the planet now, and the door in the hotel to the Snowcap Base is clear evidence of this. When their conversation is interrupted by the arrival of Sebastiene and Baris he repeats this suspicion. Baris tells the Doctor that he saw Sebastiene killed in front of his eyes by Weimark but Sebastiene shoots him before he can finish, and Baris glows red before vanishing. Donna runs forward but Sebastiene kicks her leg and she falls. He says that the ‘gun’ only transmatted Baris elsewhere and that his resuscitation was due to nano-technology in his body. When he tries to transmat the Doctor, however, n othing happens and the Doctor asks him why he thinks Weimark tried to kill him when his obvious shot would have been Baris standing next to him. The Doctor offers Sebastiene his help and suddenly Sebastiene sees sense and accepts.
The Doctor suggests to him that Sebastiene is just another robot, programmed to think he is organic. Part of his programming meant that he couldn’t tell who was who, the Doctor or Baris, when both the Supervisor and the Butler could. To prove him wrong Sebastiene communicates with the Butler who merely says he no longer responds to Sebastiene’s orders. Donna realises that the whole game has been set up by Planet 1 because it wants to replace Sebastiene with the Doctor. An explosion on the upper levels indicates that the robots are now hunting their former master. Sebastiene tells the Doctor that the TARDIS is where he landed in the snow, hidden under a cloaking device.
The Butler has started the sequence to reinstall the IMT again and has three armies of robots closing in on the Snowcap Base. He is waiting for the moment when the Doctor takes over the planet and gives it a new purpose, a chance to do something good in the universe. Meanwhile, Sebastiene leads the Doctor and Donna to the surface where they find the place where the TARDIS landed. Sebastiene uses a bracelet device to bring it ba ck into view but when the Doctor opens the door he sees it is nothing more than an empty wooden box. A fleet of atmosphere craft begins to land around them.
The Doctor, Donna and Sebastiene are ferried back to the chateau by atmosphere craft. Donna and Sebastiene are secured by energy bonds next to Baris while the Doctor is bio-checked to see that he is the right man. An alarm sounds and the Doctor says he is actually a robot bomb. The real Doctor and Sebastiene appear briefly, free Baris and then disappear with him instantly. The Doctor bomb dives into the heart of Planet 1’s technology while the Sebastiene and Donna robots smile. All three explode.
The Doctor, Sebastiene and Baris drop onto the snow together. Then Donna appears with the TARDIS. They all giggle at their use of the IMT, now back on line, and the gullibility of the planet that allowed them to build robot replicas and use them as weapons. The Doctor says it is time to go and that he is taking Baris with him but Sebastiene has to stay because he is a construct of Planet 1 and will not exist away from the planet. Sebastiene does not believe him and produces a sword. Before they can argue it out the final surviving hunter, The Carpalian Witch, grabs Donna. The Doctor thinks that this is odd, as her target ought to be one of the two Doctors or Se bastiene, but definitely not the woman she has taken. Stung into action, the witch dives at Sebastiene and the two of them fight, causing severe injuries to each other before plunging through a hole into a laboratory beneath the snow. The Doctor steps forward to help but Baris dumps him on his backside and says that it is his turn to go to the rescue. He says he owes a lot to Sebastiene then jumps into the hole.
In the TARDIS the Doctor is brooding. Donna guesses that he is worried about Sebastiene. The Doctor reassures himself that Sebastiene and Baris will end up running Planet 1 again. Donna reasons that Sebastiene couldn’t have left the planet anyway but the Doctor’s expression tells her otherwise. She accuses him of lying but he shrugs it off and says it was all too complicated, before setting the controls and heading for somewhere warmer.