In the TARDIS control room, the Doctor is becoming impatient with Lucie. Eventually she appears, resplendent in the costume she’s chosen for their planned trip to see the Moulin Rouge. They’ve nearly landed when the TARDIS engines seem to cut out suddenly. They check the scanner and it confirms that they’ve arrived in Paris, but the area is in a blackout and the TARDIS is hanging mysteriously in mid-air. The Doctor suspects there’s an obstruction in space-time so he suggests they dematerialise and try for 1899 again - but then a massive power source drags the ship out of the sky and they come crashing down to Earth with a bang.

The Doctor and Lucie emerge relatively unscathed and he apologises for the fact that the gyroscopic controls only kicked in 12 inches from the ground. It’s the dead of night and the street is dark and quiet. The Doctor checks for the power source that brought them here, but instead he stumbles across a poster signed by Commandant Ernst Schaumburg, announcing that 50 hostages will be shot in retaliation for the murder of a member of the German High Command. They realise they must have landed in the middle of Nazi-occupied Paris! They head straight back for the TARDIS only to discover it’s gone and has been replaced by a fairground carousel. The Doctor suspects the chameleon circuit must have accidentally engaged, but the carousel is extremely conspicuous and is likely to bring the entire German army down on them if they don’t hurry up.

Elsewhere, Major Treptow of the Gestapo, is interrupted during his dinner with news of another unidentified signal in the skies above Paris. He remains sceptical as the last time it turned out to be nothing more than a flock of seagulls, but when he makes contact with some of the nearby position finding bases to get the signal triangulated, he learns that the transmission is coming in on numerous frequencies. They’ve never seen anything like it before and Treptow wonders if it could be a new kind of Allied aircraft. They eventually track the signal down to Sector 7, close to Montmartre, but the district of Pigalle is a maze of streets and the device could have landed in any of them. There have been no reports of enemy planes crashing in the area or even sightings from their own observers, which amazes Treptow as he imagined a secret Allied aircraft would have stood out more. He orders the radio tracking car to be brought round and tells his Leutnant they’re going to track down and apprehend the crew themselves.

The Doctor and Lucie have been unable to find the entrance to the TARDIS, so eventually Lucie climbs up onto one of the carousel horses. As the music gets louder and the device starts to speed up, she thinks it might be quite cool flying round the Universe like this instead of in an old police box. The Doctor realises the carousel isn’t the TARDIS at all but a quantagram, a sort of physical hologram that’s real yet not real, like a stage set at a theatre. He warns Lucie, but it’s too late as it’s now going too fast for her to get off.

Doc Baroque tells his mother that he disguised the capsule before the Nazis could discover it, but she rebukes him and says a fairground carousel is just as likely to attract attention. He bleats like a goat and she slaps him, then orders him to hide the capsule behind a less conspicuous quantagram. Just then they hear Lucie screaming for the Doctor and see her on their scanner, riding one of the horses. Doc Baroque starts to drool over her image, unable to control himself during the hunting season. They see the Doctor and realise he must be the pilot. Mother Baroque orders her son to translocate the woman here…

The Doctor calls for Lucie to jump down, but before she has time to act, she screams out and vanishes into thin air. Moments later, a convoy of German vehicles arrives in the street and Major Treptow immediately places the Doctor under arrest.

Lucy wakes up groggily. She opens her eyes and realises she’s in a theatre dressing room, although it smells more like a farmyard. There’s a knock on the door and when a handsome man enters she mistakes him for Ewan McGregor and is instantly smitten. She suspects she must have either banged her head when she fell off the horse or else she’s having a dream. The man calls for assistance in loosening her corset and is shocked when she invites him to do it himself. Doc Baroque responds to the man’s calls - but when Lucie sees him she starts screaming uncontrollably. The handsome man calms her down and tells her she has a beautiful scream. Doc introduces himself as the Master of Ceremonies at the Théâtre des Baroques. Lucie asks him if he really does have the head of a goat, but when he tells her the theatre is noted for its use of illusion, she accepts that it must be make-up. She tries to leave, but Doc tells her the streets are filled with Gestapo and she won’t get far without any papers. In any case, they’ve decided she will appear in tonight’s play in the role of a prisoner in a dungeon during the height of the French Revolution. The handsome man suggests she go on stage and do her part, then afterwards he promises to help her. Lucie points out that she doesn’t know her lines so Doc tells her to improvise and assures her she’ll be playing against the finest actor in Paris - none other than the handsome man himself, Max Paul, “the idol of every girl in France“. Max is confident that so long as Lucie follows his lead, the audience will love her. He flirts with her and she’s immediately taken in by his charm.

At the Gestapo HQ, Major Treptow is intrigued to discover the Doctor has no papers. After examining the sonic screwdriver, he concludes that it must be a weapon of some sort and demands to know who the Doctor’s working with and where he’s hidden his aircraft. Unfortunately for the Major, he’s pointing the screwdriver at his own head when he inadvertently activates it. As he cries out in pain, the Doctor snatches it back and uses the opportunity to make his escape. The Leutnant returns from securing the perimeter just in time to see the Doctor disappear, and he opens fire with his machine gun…

The audience at the Théâtre des Baroques wait nervously for the performance to begin. Rumours have already spread that this is their most terrifying play yet and some have said it’s the worst thing they’ve ever seen. From behind the curtain, Lucie is horrified to discover the theatre is completely packed, but Max does his best to reassure her. They’re joined by Mother Baroque, who also has the head of a goat, who tells Lucie she’s looking forward to hearing her scream later. The woman then with her son, Doc, that everything is ready for the performance and he tells her it is - including the guillotine.

The curtain rises and the everyone gasps in shock when the famous Doctor Baroque takes to the stage. He warns the audience that something truly terrifying is coming their way but assures them they have a physician attending in case it proves too much for the faint hearted. He tells them tonight’s play, called ’The Executioner’s Son’, concerns the Reign of Terror and features a man who has died on stage 10,000 times. He proudly introduces the star of the Théâtre des Baroques, the most assassinated man in the world, Max Paul…and accompanying him on stage for one night only, the spirited Lucie Miller from Blackpool in England. The audience cheers as the story begins in the condemned cell of the Bastille…

Max Paul’s character finds his beloved Lucie, who he has loved since they were children, playing together in the fields of Provence, imprisoned and manacled. Unfortunately the audience starts to laugh as Max has to prompt Lucie and she ends up improvising with very 21st century language. Backstage, Doc and some of the other performers are unhappy that Lucie seems to be sending their play up, but Mother Baroque thinks she’s very good as it presents the audience with the necessary comedy before the tragedy. In any case, she’ll be screaming soon enough and when that happens the other humans will soon follow! On stage, Max produces a pair of scissors and tells Lucie he needs to cut her hair off to prepare her for the guillotine. She refuses to co-operate so he pulls her hair up and hides it beneath his soldier’s cap. He tells her they have to exchange clothes so that he may go to the guillotine in her place, but she won’t undress in front of so many people, so he reluctantly allows her to remove her clothing in the “next room”. Then he persuades her to leave the prison, declaring that the angry mob shall have his blood instead of hers… The other performers wonder why Max and Lucie don’t just get on with it, but Mother Baroque is happy with the way the act is increasing the audience’s anticipation.

The Doctor flees through the streets of Pigalle, carefully avoiding the German vehicles that have been sent out to re-capture him. Suddenly he’s stopped in his tracks by a mysterious figure that emerges from the nearby shadows. The man tells him he has all the hallmarks of someone on the run from the Gestapo and if this is so, he knows of a place where he can hide out and be safe. The man says he has tickets for all the local theatres and although the Doctor initially turns the offer down, he remembers saying earlier that the quantagram was like a stage set at a theatre. The Doctor accepts two tickets for the Théâtre des Baroques, which the man tells him is the nearest to their current location - but just then Major Treptow and the Leutnant arrive in their car and spot their prey. Unable to access the alleyway in their vehicle, the Major orders his men to follow the Doctor on foot, but by then it’s too late and he’s disappeared again in the warren of streets.

The play at the theatre has reached the stage where the ’executioner’ needs to decide whether he should go ahead and kill his own son. Max’s character pleads with his father to do it, explaining that the mob are baying for blood - a cue for the audience to join in by shouting and jeering. Eventually it’s time for the moment of Max’s execution and the Baroque children bleat with bloodthirsty excitement as the guillotine is brought forward. Max contemplates for a moment then steps forward and takes his place at the guillotine. Moments later, the blade rushes down and Max’s head is cut clean from his body. There’s an uncomfortable pause before Lucie whispers to Max…and then it slowly dawns on her that his execution was for real. She screams in absolute terror and shortly after that the audience joins in with their own genuine screams. Doc Baroque arrives on stage and order Lucie off stage before bidding the audience goodnight.

Backstage, Lucie believes something must have gone wrong with the performance, but when Doc congratulates her on her beautiful scream she accuses them all of being sick. He starts making arrangements to take the body away and asks Lucie to collect the head, but she’s had enough and decides to leave straight away.

The Doctor arrives at the theatre just as the audience is leaving in a state of shock. One woman, Helene, asks for his help as her husband, Roger, appears to have had a heart attack. He examines the man and concludes that he’s suffering from nothing more than a panic attack. Just then Lucie arrives and Helene criticises her for her poor performance. Lucie tells the Doctor what just happened and says the ‘executioner’ cut Max Paul’s head off for real, but the Doctor has heard of the actor’s reputation as the most assassinated person in the world. He explains that in his past performances, Max has been cut into pieces, crushed, shot by a firing squad, stabbed, strangled and burned. Lucie insists that it wasn’t a special effect, but the Doctor assures her it was all an illusion. As they head for the actor’s dressing room, the Doctor tells Lucie his priority is getting the TARDIS back. He guesses it can only have been translocated a small distance, but it’s probably disguised again with another quantagram. They finally track down Max Paul, who seems to have miraculously recovered from his recent beheading. The actor greets Lucie warmly, but she’s angry with him because of the way he deceived her. Ignoring the Doctor’s warning, she leans over and slaps him…

The Leutnant reports to Major Treptow that his men have been unable to locate the Doctor. The senior officer ponders the problem and realises their prey would want to loose himself in a crowd. The theatres will be turning out about now, but there are so many in this area it’ll be impossible to check them all. However, Treptow knows the Théâtre des Baroques is in town and he remembers Doctor Baroque from his time in Berlin when he was of some assistance to Reich Marshal Goering. He’s a master of illusion and one of his main tricks is using camouflage techniques to make aircraft disappear. Treptow orders the Leutnant to bring his men and follow him…

Max tells Lucie that being the Scapegoat is a great honour, but it’s not without its inconvenience. The Scapegoat is part of his people’s tradition and the individual who holds that position is required to suffer on behalf of the rest of the tribe before being driven out into the wilderness. The Doctor realises it was Mother Baroque who dragged his ship to Earth and that the technology used to hide it from him is the same as that being used to hide Max’s scars. Lucie wonders how they were able to stick Max’s head back on after it was chopped off and the Doctor realises they must be using a quantic reanimator to heal his injuries by turning back time. Unfortunately this always leaves behind a ghost of the injury that never happened. Mother Baroque assures them that Max is happy with his lot and he meekly agrees. Doc arrives and the Doctor asks why his ship was brought here. Doc reveals that he knows the Doctor is a Time Lord and that his ship is a TARDIS. Just then, they hear the Gestapo arrive at the theatre and Major Treptow begins instructing his troops to search the entire building. Mother Baroque orders her son to get rid of them.

While searching the rooms, the Leutnant is surprised to find restraints and handcuffs, but Treptow realises they’re props from the “revolting” plays that are performed here. He believes the Théâtre des Baroques offends all public decency, but the Gestapo has been unable to remove them like the other “degenerates” because the Baroques have friends in high places. He gives orders for the search of the theatre to continue.

The Doctor tells Lucie and Max to hide and keep quiet. He’s not quite sure what the Baroques are up to, but he knows the situation won’t be improved by having the Gestapo trample all over the place in their jackboots. He also knows the Germans have the equipment he needs to help him locate the TARDIS, so he emerges from the dressing room whereupon he is immediately pointed out to Major Treptow by Doc. The Doctor puts his hands up and surrenders, then taunts the officers that they must feel quite at home here surrounded by instruments of torture. Treptow refuses to be goaded and insists that he’s a professional interrogator. Doc claims he was just about to hand the prisoner over to the Germans after the Doctor came to him to ask for assistance in hiding his aircraft. Treptow appears to accept his story, but warns him that if he’s a traitor, not even the influence of a Reich Marshal will be able to help him. Before they take the Doctor back to their HQ, Treptow demands that he hand over the sonic screwdriver and tells him the effect he suffered earlier was mild in comparison to what’s going to happen to the Doctor later…

Mother Baroque warns Doc that the Major is a dangerous man and they should keep on the right side of him, but her son is confident that Treptow will need his help in discovering where the TARDIS is. As for the Doctor, it’s not a question of whether his captors let him live, but whether he’ll still be in one piece when they’ve finished with him. This inspires him to think of a new play for the Théâtre des Baroques based on the experiences of a prisoner of a Gestapo. His mother reminds him that there won’t be any more plays if they don’t hurry up and put their main star back in the reanimator.

Max shows Lucie the device they use to keep him alive after each of his deaths. The reason the clan Baroque brought the TARDIS here is because the quantic reanimator is becoming less effective and it can only be restored by siphoning power from another time machine. They projected a quantic beam into the Vortex to stop any passing time ship in its tracks and soon, the cycle will begin again - but Max says he won’t be here to see it. His body can’t cope with the reanimator running at reduced power and tomorrow night will be his final performance. After that, his people will need to choose a new Scapegoat…

At Treptow’s request, the Doctor has been kept awake all night. The next morning, the Major visits him in his cell to begin the interrogation, but he’s not happy with the answers he‘s getting. The Doctor insists, for example, that it’s pure coincidence his Air Force serial number just happens to be exactly the same as the licence plate number of the Major’s own car. Treptow is also sceptical when the Doctor assures him his “aircraft” is unarmed, but after that the Doctor refuses to answer any more questions. In his own mind, Treptow is satisfied that the Doctor is an RAF scientist testing a secret prototype with a camouflage system that allows it to merge with its surroundings.

Lucie wakes Max up and tells him she has a plan. She suggests he use the quantagram to disguise her as a storm trooper so she can get into Gestapo HQ to rescue the Doctor. When he points out that she wouldn’t have the authority to release a prisoner, she suggests she adopt Reich Marshal Goering’s appearance instead, but her female Northern accent might prove to be a stumbling block. She asks Max if he’d take on the role instead…

The Doctor eventually confesses to Treptow that he was piloting a self-camouflaging experimental aircraft. He says his mission was to pick up one of their agents and take her back to London, but by now his craft will have been hidden by the Resistance and it could be anywhere. He suggests they let him re-tune their tracking equipment so he can pick up its signal.

Max takes Lucie to the quantagram machine, but just as he starts going through the instructions they’re caught red-handed by Mother Baroque and her son Doc. They wonder why Max would be willing to help Lucie and conclude that he must be in love with her. Doc says he can’t wait to tell the rest of the clan so they can make his last day hell. He suggests they could do something really special for the show - like tear Max limb from limb. Lucie protests, but they tell her that in every family, in every school and in every workplace, there’s always a Scapegoat, someone that everyone else picks on. The clan Baroque believe this to be the way of nature, so rather than pretend it doesn’t happen, they revere their Scapegoat. Max asks Lucie if she’s ever met people before who seem to be life’s victims, who always seem to be unlucky and have bad things happen to them? There will always be people who do things and people who have things done to them - hunters and prey. The Baroques wonder which one of those Lucie is, but as they approach her, Max pleads with them not to hurt her…

Treptow is becoming impatient. He and the Doctor have spent hours in the car driving around the streets of Montmartre, trying to track down the camouflaged aircraft. The Leutnant believes they’re going round in circles, but the Doctor insists they‘re following a systematic pattern. Eventually they arrive at the Place du Tertre and the Doctor orders them to stop the car. Treptow points out that there’s nothing here but pigeons, but the Doctor has spotted two Morris columns which, unusually, are standing side by side. He believes one of them is his craft, but which one of them is it? Morris columns are traditionally used as advertising billboards, so he deduces that it’s the one covered in out-of-date posters. Treptow asks to be shown the cockpit, but to do that the Doctor will need his sonic screwdriver. Over-excited, the Major agrees to hand it over and the Doctor activates the device - causing the valves in the frequency tracking device aboard the German car to explode. In the smoke and confusion, the Doctor is able to escape from his captors and enter the TARDIS. Resistant to machine-gun fire, the ship dematerialises. Treptow is devastated - his prisoner has got away and he’s lost any chance now of escaping his assignment in Paris.

The next performance at the Théâtre des Baroques is due to begin in five minutes. Lucie has been tied to a rack, which Doc assures her is a genuine antique from the Bastille, as if that’s some consolation. He tells her his mother is casting the quantic beam again tonight in the hope of ensnaring another time capsule. Max arrives to say goodbye to Lucie, but she pleads with him to accept that unless he does something, he’s going to his death. It’s no use and he leaves to prepare for his performance, convinced that somehow he’s about to do an honourable thing.

In the audience once again are Helene and Roger, the man who suffered the panic attack the previous night. The curtain rises and Doc Baroque takes to the stage. He begins by making a joke at his own expense, fully aware that his appearance (goat’s head, horns and hooves) are unnerving to the crowd. He then announces that they’re about to watch Max Paul’s last ever performance and that tonight, the man who’s been assassinated 10,000 times, will die for the final time.

From behind the stage, Lucie listens as Max Paul begins another rendition of yesterday’s scene which is set in the Bastille at the height of the Terror - but this time her part has been taken by Mother Baroque herself. Lucie is furious, but then her attention is taken by the familiar sound of the TARDIS engines. The ship materialises in front of her, still in the shape of a Morris column. The Doctor emerges and apologises for the delay, explaining that he had to dodge another quantic beam in the Vortex. He changes the TARDIS back to its original police box form and then starts releasing Lucie from the rack. He tells her he also took the opportunity to do some speed-reading about an alien race called the Baroks. They’re fascinating people and their story goes right back to ancient history. Lucie interrupts and tells him they have to act immediately if they’re going to save Max.

As the play reaches the bit where Max announces that his destiny is with Madame Guillotine, Lucie races onto the stage and demands that they stop! Mother Baroque is furious, but Helene and Roger think this must be part of the act as they recognise Lucie from the previous night’s performance. Max tries to convince Lucie that his sacrifice is necessary, but the Doctor joins them on stage and says it’s the worst thing he could do. The Doctor turns to the audience and annou8nces that he’s here to tell them a story of blood, horror and pointless, endless death. Doc Baroque rushes over to bring the curtain down, but Lucie spots him and a struggle ensues.

The Doctor says that a long time ago on a world far removed from here, there lived a species known as the Baroks. They were an advanced, intelligent species, but they were at the mercy of their biology, for when the hunting season came they changed into wild, ferocious cannibalistic animals. In order to survive, they siphoned their bloodlust into ritualised form, each tribe nominating a Scapegoat onto whom they could project their natural tendencies. Each Scapegoat would suffer so that the rest of their tribe wouldn’t tear each other apart. When a catastrophe befell their planet, the surviving clans were dispersed across the galaxy and one tribe came here, to France.

Unfortunately the audience isn’t interested in the Doctor’s story and one by one, they start jeering and heckling, calling for more blood. Doc Baroque is too strong for Lucie and it’s not long before he overpowers her. He confirms to the Doctor that when the clan first arrived here, they found a feudal society and prey was easy to find. Nowadays the Baroks are strictly legal and they even join in the food queues along with everyone else. The Théâtre des Baroques is simply a way of keeping their old traditions alive - and it helps to pay the bills too. The Doctor argues that they’ve evolved and outgrown the need for a Scapegoat, but Max asks him if he knows of any victim, any ‘scapegoat‘, who’s ever been able to change their destiny. The Doctor offers himself as an example - the black sheep of the Time Lords who never fitted in and was driven out by his own people. Since then he’s changed eight times and has learned that tragedy doesn’t have to mean the end, it can mean a new opportunity. Max says his people are relying on him, but the Doctor says it would be better for them to return to their homeworld. He says he’s visited their home and it’s blooming now. The Doctor turns back to the audience and announces there will be a short intermission.

In private, the Doctor tells Doc Baroque that he visited their homeworld just half an hour ago, and although it’s clear the planet had been visited by some cosmic catastrophe thousands of years ago, it’s perfect for them now. Doc is intrigued by thoughts of howling in the woods and running free and wild again, but his mother insists there must still be a Scapegoat to preserve their traditions. Lucie reminds them that the quantic reanimator is out of power, so they can’t carry on the way they have, but Mother says the Doctor has the ability to regenerate and can become their new Scapegoat. The other Baroks grab hold of the Doctor, ignoring his protests that his regenerative powers won’t allow him to grow a new head if it gets cut off. Mother Baroque points out that they can still burn, gas and poison him over and over again. However, the old Scapegoat must die first and the audience is still crying out for a show…

Suddenly the audience screams as the Gestapo burst into the theatre, firing off a few warning shots from their machine-guns. Major Treptow calls for silence and orders everyone to remain in their seats during the security check. Behind the curtain on the stage, the Doctor tells Mother Baroque they’ve run out of time, but she refuses to listen and decides to give the audience the blood they’ve been baying for. Treptow decides to close down the theatre and gives orders for everyone backstage to be arrested. In the audience, Helene and Roger aren’t sure whether all this is part of the act, but they decide to keep their heads down just in case. The Leutnant orders Mother Baroque to assemble all her players, but as they emerge from the shadows, the officer realises with horror that they’re all goat-headed demons. Treptow tries to assure him it’s just a trick, but then Mother Baroque gives orders for her clan to kill the invaders.

The soldiers open fire as the Baroks approach and the Doctor knows the aliens can’t defend themselves against bullets. They’re about to witness a terrible slaughter unless they can somehow give Major Treptow what he wants - the invisible aircraft! The Doctor asks Max to show him how to work the quantagram machine while Doc is sent to call off the Baroks and lead them to safety backstage where Lucie can let them into the TARDIS…

Doc tries to summon his clan away, but Mother Baroque refuses to listen and says they’ve always lived their lives as hunters and that’s how they should die. Suddenly one of the Gestapo opens fire and she’s killed instantly. For a moment the other Baroks are fixed to the spot in shock as Treptow orders them all to surrender, but then one by one they race to join Doc backstage. The Gestapo officers are about to follow them when Doc raises the curtain. To Teptow’s surprise, he realises he and his fellow soldiers are in the middle of the stage facing a packed theatre audience. Alongside them is the Doctor, standing proudly before a Morris column. Treptow suspects a trick, but the Doctor assures him he’s here to give him what he wants in return for an end to the killing. The Major orders his Leutnant to cover the Doctor and shoot him if he moves a muscle. However, the Doctor points out that he’s standing on a theatre stage right over a trap door. He calls to Max, who operates the device, and then he disappears completely from sight and drops down into the area beneath the stage. The audience begins to laugh at the suggestion that the Gestapo have come here in search of an “invisible” aircraft shaped like a column, which infuriates the Leutnant to the extent that he becomes hysterical. To save face, Treptow insists on opening the ‘door’ to the Morris column, but he soon realises none of them know how. He turns to the audience and yells at them to stop laughing at him, but it has no effect. This may not have been the show Roger and Helene came here to see, but they have to admit it’s extremely funny…