On the planet Skaro, the Emperor Dalek finalises plans to conquer the Earth. The mercenary leader Karl confirms that his men are ready to leave and promises there’s no finer band of cut-throats in all the galaxy. The Cyber-leader states that the Cybermen are always ready, so the Emperor Dalek warns both groups not to fail the Daleks. Karl has intercepted an emergency signal summoning the Doctor back to Earth, but the Emperor says this was always their intention. The Cyber-leader believes the Doctor is too dangerous and should be destroyed, but the Emperor Dalek says they need him alive until their plan is complete. After that, he will pay the penalty and be exterminated for his crimes…

The TARDIS materialises in the back garden of 10 Downing Street and the Doctor urges his companion to hurry as he knows “the lady” doesn’t like to be kept waiting. Entering the Prime Minister’s office, the Doctor greets Margaret warmly and notes that she’s working late again as usual. Mrs T demands to know what he’s doing here and tells him she intended him to go to Number Ten, a nightclub in Clarendon Square. The Doctor introduces her to his latest companion Jason, who he acquired on a recent visit to revolutionary France - which is just as well as the young man was about to lose his head. Jason kisses Margaret’s hand and explains that the device on which they received the message was unreliable, like most things in the TARDIS. Mrs T tells the Doctor that the most important peace conference in Earth’s history begins tomorrow and there’s a real chance they might achieve mutual disarmament and lasting world peace. The American envoy will be the key figure as he’s the only person trusted by all the major players. However, MI5 has discovered evidence of a plot to kidnap the envoy and blow the conference to smithereens during his opening speech. The agent who discovered this was murdered, but before he died he revealed that the danger came from beyond Earth. The envoy wishes to attend the opening night of a nightclub owned by a friend of his and Mrs T wants the Doctor to escort him. He assures her she can depend on him, then he leaves with Jason. Once they’re out of earshot, the Doctor confides in Jason and says he can cope with most things in the cosmos - from Daleks to dinosaurs - but Mrs T literally terrifies him!

At the Number Ten nightclub, singer Crystal prepares for her opening performance. She’s come straight from her European tour and this is her London debut, so understandably she’s nervous. The MC tells her a VIP, the American peace envoy, wants to meet her and he points to a distinguished looking gentleman at a nearby table, surrounded by gorilla-sized bodyguards. He introduces her to the envoy, then it’s time for her to take to the stage. As the audience applauds, Crystal performs the song “Strange Attractor”, but as she finishes the nightclub is invaded by Karl’s mercenaries who materialise from nowhere and start firing laser guns. The MC tells Crystal to take cover as the group charges through the audience looking for their target. The envoy’s bodyguards put up quite a fight, but Karl tells the mercenaries not to worry as he’s already sent for reinforcements. Suddenly a group of Cybermen appears and they march relentlessly towards the envoy. The bodyguards are no match for the Cybermen’s weapons and it takes mere seconds for them to grab their prisoner.

Karl watches as the invaders disappear, taking the American envoy with them. Just then, the TARDIS materialises in the middle of the dance floor and the Doctor emerges, demanding to know what’s going on. Karl mocks him for arriving too late, then he activates a device and he too disappears. The Doctor asks the MC and Crystal what happened then he tells Jason they need to rescue the envoy. They only have 12 hours before the peace conference begins, but he thinks he can track the kidnappers down using the space radar in the TARDIS. One of the mercenaries is still alive and, realising he’s from Deneb Three, the Doctor is able to talk to him in his native language. Before the man dies, the Doctor learns that the mercenaries were due to enjoy a farewell drink at Delilah’s. Crystal is confused and demands to know what’s going on, but she’s angered by Jason’s patronising attitude and follows him into the TARDIS…

In the control room the Doctor has picked up the kidnappers’ trail and locks the TARDIS onto their energy track. To his horror he sees Crystal has joined them inside and he rebukes Jason for wasting time with his amorous pursuits. The Doctor tells Crystal they’re on an important mission that involves the safety of her planet and he orders Jason to get rid of her, but she refuses to leave. In their struggle, her hand accidentally touches the launch controls which sets the TARDIS in motion. There’s no time to take her home, so whether she likes it or not, it looks like Crystal is going with them…

Karl brings the envoy before the Emperor Dalek and says he’s happy to continue working for them so long as they pay him. The Emperor orders the envoy to be taken to the high security area, but mistaking Karl for a fellow human, the terrified American pleads with him to help. Karl refuses and tells him that business is business. He then reassures the Emperor that he deliberately left a clear energy trail to Altair III where the Cybermen are laying a trap for the Doctor. The Cyber-leader demands to know why the Daleks want the Doctor alive, but the Emperor refuses to reveal his plans. The Cyber-leader insists that the Cybermen are their allies, not their servants, and without their help the kidnapping would have failed. They wish to destroy the Doctor immediately, but the Emperor says he’ll be exterminated only when they’re ready…

Jason asks the Doctor about the huge silver creatures that Crystal described and he identifies them as Cybermen. He checks the sensor and, thanks to an exceptionally clear energy trail, he discovers they’re heading for Altair III. The Doctor visited the planet a few hundred years ago and is about to explain why he thinks it’s a strange place for the kidnappers to go when Crystal interrupts and insists everyone stop with this illusion. She assumes the Doctor is a stage magician and thinks everything’s done with mirrors, but as the Doctor tries to explain the facts, the TARDIS arrives at its destination. Crystal has heard enough and demands to be let out. Confident she won’t come to much harm outside, the Doctor opens the door while he tries to get a more precise fix on the Cybermen. Jason decides to go outside to check on their new friend.

Outside the TARDIS, Jason finds himself in a weird jungle surrounded by green gloom. He calls out to Crystal and finds her in a state of shock. She points to something glowing and burning in the distance and Jason thinks it might be a live volcano. Crystal is amazed and it suddenly hits her that everything the Doctor and Jason told her was true - they really are on another planet. The two of them become better acquainted and when she compliments Jason on his accent, he explains that his mother was English and that he went to school in England. In fact, he didn’t return to his birthplace in France until the revolution, which would have been a fatal mistake if he hadn’t met the Doctor there.

Suddenly Crystal screams as she sees giant insects hovering above them. They have fierce looking human faces, but have fangs, claws and wings. Jason says they must be one of the local lifeforms and he guesses the Doctor will want to make friends with them. He waves to the insects, but their response doesn’t look particularly friendly. The youngsters move slowly back towards the TARDIS, but the insects suddenly dive down and literally pick Crystal off her feet. Somewhere in the gloom Jason hears the Doctor calling their names and he rushes over to explain what’s happened. The giant insects appear to be carrying Crystal towards the volcano and it looks like they’re preparing to drop her in. Much to Jason’s surprise, the Doctor starts making loud squawking noises, which he explains is the insects’ language. Moments later, the insects come back and gently lower the shocked Crystal down to the ground. She’s furious with Jason for telling her the creatures were harmless, but he reminds her that she was the one who insisted on leaving the ship. The Doctor tells them both to be quiet as he needs to have a very important conference. He continues squawking to the insects, then he thanks them and bids them goodbye. The insects told him the spaceship they’re after touched down in a clearing not far away and a prisoner was transferred to a second ship which immediately took off. The Doctor reveals that he visited this planet 100 years ago when the Daleks were trying to establish a base here and he stopped them from destroying the forests and wiping out the population. As a result, the insects made him an honorary member of their colony.

They only have hours left to rescue the American envoy, so they head back to the TARDIS - but before they can move, they find themselves surrounded by Cybermen who insist that the Doctor comes with them. The Doctor demands to know who gave them their orders and asks why they’ve kidnapped the envoy, but the Cybermen tell him only one question is important - will he surrender or die? To their surprise, the Doctor starts making loud squawking noises again and the giant flying insects immediately return and begin attacking the Cybermen. While their captors are distracted, the Doctor leads his companions back to the TARDIS.

The ship dematerialises and the group recover from their uncomfortable experience. Jason returns to the control room with the dressing-up chest the Doctor sent him to find. They’re baffled as to why the Cybermen are working alongside mercenaries and their only lead is Madame Delilah’s, where the dying man said his colleagues would be celebrating the success of their mission. Delilah runs the Bar Galactica on Sentros, an underground hangout and well-known recruiting centre for outlaws, murderers and mercenaries. The Doctor tells Jason and Crystal that he hopes Delilah might be persuaded to talk if she thinks they’re fellow mercenaries, so he rummages around in the dressing-up chest (rejecting things like a ridiculously long scarf) until he finds suitable disguises for himself and Jason that fit the description perfectly. Crystal asks to be join them and although the Doctor tells her the Bar Galactica is too dangerous, she suggests they may be looking for a singer. Despite the Doctor‘s protests, she soon finds a costume of her own from the chest.

The Cyber-leader returns to Skaro and tells the Emperor Dalek that his Cyber patrol returned from Altair III without the Doctor as the natives of the planet assisted his escape. The Cyber-leader insists that the blame lies with the Daleks’ orders and says it would have been safer to kill the Doctor on sight, but Karl tells them there’s no point in blaming each other and says they should start making plans to recapture him. The Doctor now knows they’re using mercenaries and Karl is sure he’ll know where most of them are recruited. He’s probably on his way their right now, but fortunately time is against him…

At the Bar Galactica, Madame Delilah - an opulent lady with a low-cut ball gown - is entertaining the patrons with her rendition of the song “Business is Business” when the Doctor enters with Jason and Crystal. Suddenly the room goes quiet and everyone turns to stare at the new arrivals. It’s clear the patrons don’t like strangers, so the Doctor tells his friends to scowl back until they get used to them. The place reminds Crystal of a Wild West saloon, but Jason says he’s never seen a more villainous looking gang of cutthroats in his life. He spots a small furry creature wiping the tables and collecting glasses and the Doctor identifies it as a native of Deneb Four, a hard-working species who do the cleaning all over the galaxy. Crystal is horrified when one of the customers kicks the creature out of the way, so the Doctor intervenes before the man can kick him again. The angry mercenary turns his attention on the Doctor and moves in to attack him with a dagger, but the Doctor manages to throw the man right over the bar.

From her private booth, Madame Delilah is delighted, so the Doctor introduces himself. He says he and his friends are looking for employment and are willing to do whatever pays best. Delilah is clearly attracted to the Doctor so she invites him to join her and orders Zog, the furry creature, to bring them champagne. Jason and Crystal order their own drinks from the bar, but Crystal isn’t took keen on the sinister-looking concoction and says it tastes like liquid dynamite. Jason tries to impress her by drinking it like a man, but he too ends up choking and coughing. Although the Doctor is making a good impression with Delilah, it’s clear the two youngsters are attracting unwanted attention from the alien mercenaries. A big hairy man stares at Crystal and another creature with tentacles has its eye on Jason. When the man gives Crystal a cheeky pinch, Jason confronts him and insists that he leave his friend alone. The man tries again, so Jason gives him a hefty push, but all it succeeds in doing is irritating him. The man draws a cutlass, so Jason takes out his own sword and they begin to fight. After a few minutes, Jason convincingly wins his sword fight and consolidates his position in Crystal’s eyes as her hero - even though she knows he only won because she crowned the mercenary with a nearby bottle!

Satisfied by Delilah‘s assurances that the bar fight was just boyish fun, the Doctor continues his conversation with her. Delilah finds the Doctor to be a mature, educated and civilised man and says she’s tired of the hairy barbarians she normally meets here. She’s reluctant to waste time talking business with him and would rather the two of them make beautiful music together, but the Doctor changes the subject and soon learns that someone has been recruiting mercenaries for a big caper. Delilah continues to flirt with him and he’s forced to tell her he’s too busy with his own mercenary band who depend on him to feed them. Delilah understands and suggests he speak to Karl, the handsome wicked man who’s running the operation. Just then, Karl arrives and orders everyone in the bar to be silent. He announces they have a distinguished guest with them tonight - the most wanted man in the cosmos, a man with a bounty of a million credits on his head - the intergalactic master-criminal known as the Doctor! He holds a weapon to the Doctor’s head and tells the other mercenaries they’ll all share in the profits when he takes him in. Delilah is even more delighted as she knew there was something special about the Doctor.

Jason and Crystal are watching from across the bar, but there’s nothing they can do to stop Karl taking the Doctor. Just then, the furry creature Zog runs between Karl’s legs and trips the man over. The Doctor calls to Jason to use his blaster to shoot out the lights and as the room is plunged into darkness, he urges his friends to run back to the TARDIS. One of the other mercenaries has a clear shot at the Doctor, but Karl stops him and says they need him alive. In any case, he’s sure the Doctor won’t get far…

The TARDIS dematerialises and the Doctor says the faster they can get away from that place the better. Then, to his surprise (but Crystal’s delight), they discover Zog has accompanied them aboard the ship. Zog speaks in a strange unintelligible voice, but the Doctor can fortunately speak the language and learns that the creature no longer wants to serve at the Bar Galactica and would like to join them. The Doctor has to stop Zog from polishing his boots and cleaning the console, but Jason and Crystal have already fallen in love with him so the Doctor agrees to let him stay with them. Jason reminds the Doctor that the clock is still ticking away and they didn’t learn anything of value at the bar, but the Doctor says he found out a great deal. It was no accident the Cybermen were waiting for them on Altair III or that Karl turned up again at Delilah’s and it‘s become obvious that someone is able to anticipate their every move. Suddenly the lights start to flicker and the Doctor says the TARDIS is in the grip of a powerful outside force…

Aboard their spaceship, the Daleks pick up the TARDIS on their main vision screen. Their tractor beam has locked onto the TARDIS, but violent meteor storms are predicted in this space sector. Capturing the Doctor is their main priority so they increase the power to maximum. A transfer beam is activated and moments later the TARDIS materialises on the bridge, trapped within a force field. The Daleks tell the Doctor he is their prisoner and they order him to surrender. There’s no response, so they fill the TARDIS with a high frequency sonic beam that can destroy brains. Moments later the Doctor, Jason and Crystal emerge, clutching their ears and crying out in agony. The Doctor finally realises the Daleks have been behind everything and he introduces his companions to the most evil, ruthless, destructive creatures in the cosmos. The Daleks tell the Doctor that by interfering with their plans for conquest, he’s constantly denied them their right to be rulers of the Universe , but now he’s their prisoner his interference is at an end.

Just then, the ship is rocked by vibrations caused by the meteor storm. As the Daleks turn their attention to the controls, one solitary Dalek is left to guard the three prisoners. The Daleks struggle to maintain operations as their deflector shield is damaged - then without warning, they begin to spin around, helplessly disorientated because their guidance systems are out of control. As the others tackle the Daleks one by one and push them off the bridge, the Doctor closes the main door and fuses the lock, trapping the Daleks in the aft section. Unfortunately the TARDIS is still locked inside the force field, so the Doctor tells Jason and Crystal they’ll have to steer the spaceship while he tries to release it.

The Daleks are interrupted by a coded message from the Emperor instructing them to bring the Doctor to Skaro alive. By now the meteor storm has passed, so the Daleks continue their course back to their home planet. They order the Doctor to explain to their scientist how the TARDIS works, but he refuses to co-operate, knowing they have orders not to kill him. Instead, they threaten to kill his companions one by one, starting with Crystal, so he reluctantly agrees. He insists that he won’t help unless he can see that his friends are safe, so the senior Dalek allows them all to enter the TARDIS together.

Inside the TARDIS, the Doctor is horrified to see that the Dalek scientist has already started to dismantle the console to discover its secrets. He warns them of the harm they could do with their indiscriminate tinkering and says the power source of the TARDIS could reduce their entire battle cruiser to atomic particles. He accuses the Dalek scientist of being ambitious and the senior Dalek disciplines the scientist for his insubordination and orders him to return to the flight deck of their own ship. The Doctor says he’ll have to repair the damage before he can show them anything and points to a power cable with a frayed end that’s been broken off. As the senior Dalek moves closer to examine it, the Doctor thrusts the cable at him and he’s hit with a terrific burst of electricity. Jason and Crystal push the Dalek out through the doors and the TARDIS dematerialises. Unfortunately the Doctor wasn’t bluffing when he said the ship is in a dangerous condition and it’ll take time to fix the damage. He switches on the EDS - the Emergency Displacement System - which will automatically take them as far from the source of danger as possible and land them somewhere completely safe. Crystal decides to take a little nap while the Doctor asks Zog to help him sort through the toolbox.

On Skaro, Karl tells the Emperor Dalek that reports are coming in that the Doctor has escaped again. The Emperor orders all Dalek patrols to find the Doctor and bring him here alive. The Cyber-leader believes Karl’s plan has failed, but Karl insists the fault wasn’t his. The mercenary can’t understand why the Doctor is so important to the Daleks as they have the American envoy and the peace conference is already endangered, but the Emperor orders him not to question their orders.

The TARDIS materialises on an alien planet, but the Doctor has barely had time to start the repairs as there‘s a limit to what he can do while in flight. Crystal returns from taking a rest and asks where they are, but the Doctor has no idea where or when they’ve landed as most of the instruments are still on the blink. However, the one fact they can rely on is that they’ve arrived somewhere safe. Crystal decides to go out and explore, but she leaves before the Doctor can tell her to treat all alien planets with respect.

The moment Crystal steps outside the TARDIS she finds herself floating high up into the air. Jason rushes to help her and she tells him she only took one step and ended up bouncing around the desert like a ping-pong ball. Jason encourages her to move more slowly and eventually her feet come back down to the ground. They both sit down on a nearby rock and admire the beautiful landscape with all the different coloured sands. Jason tells her it’s not the only thing that‘s beautiful and then they begin to sing the duet “Sky High“. Jason realises he’s starting to fall in love with Crystal and he tells her that travelling with the Doctor can sometimes have its advantages. They decide to head back for the ship.

As they enter the TARDIS, the Doctor says he’s ready to take off again. Crystal excitedly tells him about their experiences outside and he explains that it’s because they’re on a low gravity planet. He needs to take the ship on another test run, but he’ll use the Emergency Displacement System again so even though he has no idea where they’ll land, he’s sure it’ll be somewhere perfectly safe. The TARDIS materialises again and the Doctor’s best guess is that they’re somewhere on Earth and that they’ve gone back in time rather than forward. The two youngsters go outside to explore while the Doctor and Zog return to their repairs. On further examination, the Doctor confirms that they are indeed on Earth and he eventually narrows it down to France. He checks the time period and discovers to his horror that they’ve landed in 1789 - right in the middle of the French Revolution. He’s brought poor Jason back to precisely the time and place where the people wanted to cut off his head…

Outside, Jason is starting to think there’s something terribly familiar about this place. Then, just ahead of them in the town square, they see something he recognises only too well - Madame Guillotine!!! From out of nowhere, revolutionary guards appear and grab Jason. They taunt the young man for not getting very far after escaping their clutches just a few short minutes ago and are delighted that the crowd of onlookers won’t be disappointed after all. Jason is dragged away and Crystal is left alone, powerless to help - but then she finds herself standing next to Zog, who’s wearing a cloak and a revolutionary cap. They watch as Jason is strapped to the guillotine, but they notice the Doctor is approaching the crowd, disguised as an old crone. The Doctor giggles at the fate of the handsome young Marquis and asks the executioner for permission to take a lock of his hair as a memento. The guard agrees, although he suggests she might just as well wait a while and then she can take the whole head. The Doctor produces a knife and climbs up onto the stage, but before anyone can stop him he cuts right through the ropes around Jason’s hands. Zog rushes forward and throws a number of smoke grenades which explode instantly. The whole area is covered with a thick fog and the guards mill around in confusion. The Doctor gathers together his companions and they all race back to the TARDIS…

Inside the ship, the Doctor apologises to Jason for sending him into such danger, but his friend is just relieved to have escaped the ordeal a second time. The Doctor is reluctant to take off again until he’s worked out what’s wrong with the Emergency Displacement System and Jason tells him it’s almost as if the device was working backwards. The Doctor checks and discovers he’s right - the Dalek scientist must have reversed the linearity of the proton flow, which threw the EDS into reverse, making it seek danger rather than avoid it. The problem was so elementary it baffled the Doctor completely, but now he knows what’s wrong, it should be easy to fix. As he and Zog get to work, Jason reminds them they don’t have much time left before the peace conference on Earth begins. They still haven’t rescued the envoy or discovered how the Daleks plan to blow up the conference, so the Doctor decides to go back to Madame Delilah’s. He’s sure he can soon clear up the rumours Karl spread about him having a price on his head and he’s confident he was starting to win Delilah over.

The TARDIS lands back at the Bar Galactica, but everything is dark and quiet. Crystal wonders if the bar is closed for the night, but Jason thinks it’s more likely the mercenaries are sleeping off their hangovers. They go to Madame Delilah’s private booth and find her there alone with a bottle of champagne. The Doctor tells her he wants to continue their rudely interrupted conversation, but Delilah is more concerned with the fact that Zog seems to have abandoned working for her in favour of the Doctor. It confirms what she suspected - the Doctor isn’t really a mercenary at all. She’s been making enquiries about him and has discovered he’s a Time Lord, one of the aristocratic elite of the cosmos. He insists that he’s a renegade and says he’s come her to ask for her help in saving a far-away planet. Delilah says there’s no profit in that for her, whereas she can gain a million credits if she hands him over. She knows he’s not the criminal mastermind Karl claimed, but she’s discovered the bounty on his head is actually real if she hands him over alive to the Daleks! The Doctor turns to leave, but Delilah pulls a dainty little jewelled blaster on him and reminds him of the mercenary motto “business is business”.

While they’ve been talking, the Doctor has failed to notice that Delilah’s men have surrounded them. The bar obviously wasn’t empty after all. Karl arrives with two Daleks and tells Delilah that he’ll take over now, but she refuses to hand over the Doctor until she gets paid. Karl tries to assure her she’ll get her money later, but she believes working for the Daleks has made him forget the rules of being a mercenary. The Daleks intervene and state that there’ll be no bounty as they’ll tell the Emperor it was them, not the mercenaries, who captured the Doctor. Karl becomes angry at their attempts to cheat a fellow mercenary and tries to convince them it’ll be in their interests to pay up. The Daleks still refuse to co-operate, so Delilah orders the other mercenaries to turn on them. A massive fight begins and the Doctor urges his companions to use the blaster fire as cover while they race back to the TARDIS.

From inside the doorway, the Doctor watches as the mercenaries are slaughtered, but as the Daleks turn their attention to him, Delilah steps in the way to protect him. She screams as she’s cut down by a Dalek blaster. Karl is so enraged he physically wrenches off the top casing of the Dalek and blasts the creature inside. The other Daleks turn to exterminate Karl, so the Doctor throws him a fire extinguisher and he uses the freezing cold carbon dioxide to disable them before they can open fire. Karl is grateful to the Doctor as he could‘ve used the opportunity to escape, and in return the Doctor is thankful that Karl didn’t stick with the Daleks while they were winning.

The Doctor attends to the dying Delilah and she tells him it was a pleasure to meet him and it‘s a pity they can‘t pursue their friendship. The Doctor is honoured and says he owes her his life. She tells Karl that the Daleks tried to cheat them and urges him not to let them get away with it. As she dies, the Doctor tells Karl it’s time he decided whether he wants to pursue revenge or profit.

Later, the TARDIS materialises in the prison area on Skaro and the Daleks prepare to take the Doctor prisoner the moment he emerges from the ship - but to their surprise, the figure that emerges from the TARDIS is not the Doctor, but Karl…and he’s accompanied by another Dalek. Karl announces that they’ve captured the Doctor and his companions, then he orders the Doctor, Jason and Crystal to step outside. Then Karl tells them the Emperor has issued new orders and their prisoners are to be taken to the high security area. The Daleks realise one of the Dalek patrol assigned to the mission is missing and the Dalek accompanying Karl tells them it was destroyed during the battle. The other Daleks leave and the Doctor’s party breathe a huge sigh of relief. Inside Karl’s Dalek is Zog and they check on him to make sure he’s still okay before resealing the casing. Crystal asks the Doctor how he was able to make Zog’s Dalek talk and he tells her he used ventriloquism and a small device that makes his voice sound like a Dalek. Karl says they need to hurry as time is running out. The Doctor tries to persuade Crystal to stay behind in the TARDIS where she’ll be safe, but she insists on seeing things through to the end.

In the main HQ, the Emperor learns that the Dalek patrol who accompanied Karl to the mercenary bar has failed to report in. He orders them to send another patrol to investigate as without the Doctor, their plan cannot succeed. The Cyber-leader questions whether the Doctor is likely to come here, but the Emperor is certain he’s already on Skaro as he knows the Doctor would never return to Earth without the envoy.

In the high security area, the Doctor locates the kidnapped envoy trapped within a light cage. He seems to be unconscious and there’s a weird glow all around him which the Doctor identifies as a laser wall. He tries to break through it with the sonic screwdriver, but it’s hopeless. He realises the reason there are no Dalek guards here is because they don’t need them. Karl suggests contacting some of the other mercenaries who are still on Skaro in case they can help, but the Doctor says it would just be a useless waste of their lives. Crystal finds a control console with recording and monitoring equipment and the Doctor guesses they’ve been interrogating the envoy. They play back a recording in which the envoy refuses to answer the Daleks’ questions and insists on being returned to Earth. The laser wall is probably controlled from the Emperor’s throne room, so Jason volunteers to sneak in and switch it off, but the Doctor warns him the base is full of armed and angry Daleks. Instead, he proposes something difficult and dangerous but it’ll mean he has to return to the TARDIS. Jason decides to stay here with the Zog Dalek to keep an eye on things and Karl offers to find the rest of his men and win them over, so the group separates. Once they’re alone, Jason tells Zog he’ll have a quick scout around, just in case the Doctor was wrong about the guards.

The Daleks report back to the Emperor with news that the second patrol sent to Madame Delilah’s have found the missing Daleks - both were dead, as were Delilah and many of the mercenaries. One of the dead Daleks had been removed from its casing. Also, Karl recently returned to Skaro accompanied by a Dalek and the Doctor’s group as prisoners, but no prisoners have been handed to the security section. It’s now clear that Karl is a traitor and the Doctor’s group are loose on the base, accompanied by an impostor Dalek. Instructions are given for all Daleks to be alerted to search the security area…

The Doctor and Crystal take a different route back to the TARDIS to avoid the Dalek patrols. They find themselves in a storage area filled with boxes and crates. They hear two Daleks outside the storage room, planning to search inside so they quickly hide inside empty crates, but Crystal is immediately spotted and the Daleks lift the crate on a hoist into mid-air. Then the Daleks open fire and the crate explodes. Incredibly, the crate turns out to be empty, so the Daleks begin searching elsewhere for the escaped fugitive. Once they’ve gone, the Doctor helps Crystal out from a different crate. She asks him how he did that and he explains that it was a simple illusion, adding that Harry Houdini himself studied under him! Jason arrives and the Doctor demands to know what he’s doing here. They hear another announcement about the impostor Dalek. An order is given for all lone Daleks to be challenged for their recognition signal and any that fail to give one will be exterminated. Jason agrees to return to Zog while the Doctor and Crystal continue on their way to the TARDIS.

The Doctor asks Crystal to wait outside the TARDIS as he’s about to attempt a rather dangerous experiment. He goes inside and the ship begins glowing and vibrating. The Doctor emerges and Crystal says she thought it was going to explode. He doesn’t know whether his experiment has worked yet, but says they’ll soon find out…

Jason returns to the high security area and finds Zog waiting patiently inside the Dalek casing. Suddenly more Daleks arrive and, seeing the lone Dalek, they approach it and challenge it for its recognition signal. There’s no response, so a final warning is given. When the Daleks realise they’re facing the impostor, they open fire and the casing is completely destroyed. Jason is horrified. The Daleks resume their hunt for the other fugitives, then the Doctor and Crystal arrive. Jason tells them what happened, but as they mourn the loss of their friend, they’re amazed to find Zog hiding nearby. The Doctor speaks to Zog and discovers he got nervous waiting on his own, so he got out and hid. Then the Doctor reveals that he’s about to create a time tunnel, the only thing that can get them through the laser barrier imprisoning the envoy. He shows them a beautiful glowing crystal pendant and says he filled it with concentrated temporal energy from the TARDIS. He warns them they won’t have long, so he asks Crystal to swing the pendant round in a giant circle while he and Jason go inside the laser cell to bring the envoy out. As the pendant swings faster and faster, a time tunnel forms right through into the cell. They manage to release the envoy just in time and the Doctor congratulates everyone.

In the Dalek HQ, news arrives that the envoy has been released from his cell. The Emperor Dalek gives orders for the Doctor to be captured…

Eventually the Doctor, Jason, Crystal, Zog and the American envoy arrive at the TARDIS - but before they can enter, Karl and his mercenaries emerge from their hiding place. It’s a trap and Karl also has the Daleks with him. He confesses that he was caught by the Daleks, so he came to an arrangement with them - a million credit bounty in return for helping to capture the Doctor alive. The Doctor isn’t surprised. For a moment he thought Karl might be something more, but in fact he’s just a mere mercenary after all.

The Doctor’s group are returned to the high security area, only this time they’re the prisoners and there are Dalek guards all around them. Crystal is resigned to their fate, but the Doctor is surprisingly confident. He tells them things are never hopeless and he remembers saying something similar to Winston Churchill once, just after Dunkirk. Churchill was in the dumps, but the Doctor managed to persuade him the British public were about to face their finest hour. The Doctor tells his friends he’s faced lots of darkest hours like this one, but he’s learned there’s always a dawn afterwards. Then a Dalek arrives and tells the Doctor he’s been summoned to face the Emperor.

The Emperor Dalek tells the Doctor this is his ultimate defeat, but this just makes the Doctor laugh. He knows the Daleks don’t want him dead for some reason but the Emperor merely says this would be too easy. Instead, they plan to force him to watch the destruction of his beloved Earth. The Doctor believes the Daleks are rankled because there have been so many failed attempts to conquer that planet, but the Emperor says he’ll only understand the truth when it’s too late. The Doctor asks him why the Daleks needed outside help from Cybermen and mercenaries, but the Emperor says they’re no more than scapegoats - they’ll be blamed for what’s happened by the Galactic Council and when they‘re no longer needed they’ll be exterminated.

The Doctor’s companions are brought in by the Cybermen and Karl’s mercenaries and although the envoy is starting to recover and can now walk unaided, he still seems dazed and isn’t talking yet. The Emperor Dalek says he’s brought them all together so they can witness the destruction of the Doctor’s TARDIS. A suspension beam is activated and the TARDIS appears above them. The Daleks open fire and the TARDIS explodes before their eyes! Oddly, the Doctor doesn’t seem remotely concerned and says the ship was getting on a bit anyway. In return, the Doctor offers a trick of his own. He produces a black box and reveals that he recorded their earlier conversation. He plays it back and the entire group listen as the Emperor Dalek explains how he’s betrayed the Cybermen and mercenaries and plans to destroy them all. The Cyber-leader orders his troops to attack the Daleks and Karl also rallies his mercenaries. Within moments the entire chamber is filled with the noise and heat of a huge battle. The Doctor gathers together Jason, Crystal, Zog and the envoy and, with the aid of Karl who provides them with covering fire, they manage to escape from the room.

The Doctor leads his friends towards the TARDIS and explains that he knew all along that it hadn’t been destroyed. It was just a Dalek illusion to make them think they’d lost everything, but he realised it was a trick because his ship is indestructible. He hurries everyone inside and tells them they have a lot to do and very little time in which to do it. Moments later, the TARDIS dematerialises…

Back on Earth, Crystal is amazed to discover they’re going for tea with Mrs T at Downing Street, but Jason is very casual about it and says he’s been here before. The Prime Minister thanks the Doctor and says they owe him and his friends a great debt. She says the envoy is understandably tired, but he’s ready and able to go ahead with the peace conference which is due to begin very shortly. After she’s left, Crystal says she needs to go back to her own Number Ten too as rehearsals are due to start soon. She prepares to say goodbye to her new friends, but notices the Doctor seems distracted. He promises to pop by later and see her performance, then once they’re alone, he tells Jason he thinks they won too easily. He knows they faced great dangers, but there were so many times when the Daleks could have killed him but they didn’t. Why did the Emperor want him alive and why was he so confident the peace conference would be blown up? It’d be impossible for anyone to plant a bomb there, but the way the Emperor Dalek spoke to him made it sound as if he himself was part of the Daleks’ plans. Jason says that doesn’t make sense because all the Doctor did was bring the envoy back to 10 Downing Street in time for the conference. Suddenly the Doctor realises what it all means - this must be exactly what the Daleks wanted all along. He grabs a phone and says it’s urgent the American envoy comes here to meet the Prime Minister immediately.

While they’re waiting, the Doctor rummages around for the voice changing device he used back on Skaro. Before long the envoy arrives to meet Mrs T and the Doctor says he’d like a word with him first. He speaks to the envoy with a Dalek voice and asks him what his mission is. The envoyn produces a silver egg-like device which the Doctor identifies as a Dalekenium bomb, powerful enough to take out most of central London. On further questioning, the envoy reveals that forged evidence has been planted at the conference incriminating each world power. They’ll all blame each other and war will begin, then the Daleks will invade after the fighting is over. The Doctor tells him his mission is cancelled and orders him to hand the bomb over, but the envoy activates the timer and the Doctor discovers they only have about 20 seconds before it goes off. The only thing that could possibly defuse it in time is tannic acid in a high temperature solution. Fortunately he has some right here - in a good, strong pot of tea.

Margaret returns and demands to know what’s wrong with the envoy as he seems to be in some kind of trance. When the Doctor explains that he’s undergone a temporary catatonic withdrawal as a result of his terrible experiences, Mrs T is horrified as the conference is about to begin and the envoy’s presence is vital. The Doctor agrees to help and uses the crystal pendant to counteract the Daleks’ brainwashing. He starts to hypnotise the envoy…

At the Number Ten nightclub in Clarendon Square, Crystal finishes another perfect rendition of the love duet “Sky High”. The audience bursts into applause and the Doctor and Jason congratulate her on a marvellous performance. Jason tells her he wouldn’t have missed it for all the world. Crystal has read in the news that the peace conference is going well and the American envoy made the speech of his life. The Doctor admits that after removing his conditioning, he may have added a little extra confidence too. Crystal asks if she can speak to the Doctor alone and tells him she’s upset that Jason hasn’t revealed his true feelings to her. The Doctor points out that they’re from different countries, cultures and times, but he says they must both work out for themselves whether they want to take the risk. He adds that he’s had many companions travelling with him over the years - Susan, Jamie, Zoe, Leela, Peri and Evelyn - but they always leave him eventually to look for their own happiness and most of them seem to find it. Crystal asks him if he ever misses them and he says he does…every single day!