The Doctor is walking with Sarah past cabinet doors but through the TARDIS in a place she doesn't know. He will give her a guided tour someday. Sarah sees an open room that looks like an enormous living room but the Doctor calls it a boot cupboard. The Doctor has seen bigger boot cupboards. She follows him, asking how big is big. He asks how big she is at the moment and she answers 5'5. There are no measurements in infinity, the Doctor tells her he doesn't know why he likes humans so much, they have such little minds. She tells him it is because he has such good taste. He tells her that is very true.

Sarah opens a door with a multicoloured Cathedral like stained glass window just like some of the roundels inside this room. Inside is a dusty, dark, wood panelled chamber with a metallic like console in the centre. The Doctor tells her this is the second control room but in fact, it is the older one. He finds a dusty frilled shirt and she plays toots on a recorder or a flute. The Doctor goes to a central column and finds switches beneath wooden flaps. The top has a kind of old fashioned shaving mirror. The Doctor puts on a light and opens a large scanner screen on the wall. He sees the whirlpool like Mandragora Helix, something he thought they avoided. It is a spiral of pure energy that radiates outwards in ways no one understands. At the centre is some kind of intelligence and it is living but that is all anyone knows. The Doctor hopes they can magnetize it enough to withdraw the pull but it gets the TARDIS. The Doctor wants them to push through it and come out the other side. He tells her to say the alphabet backwards as something enters inside her head. The TARDIS drizzles in and out but hits the center of the whirlpool vortex, passing huge rings of spiral of white crystals, a kind of helix. It seems all over but they don't know where: the astro-sextant rectifier has gone out of phase. He wants to go out, going up steps to a dark doorway out. He tells her to stay inside. Outside there is a landscape of crystals in a black void, bigger than his boot cupboard. Sarah follows him out. Their voices echo and bounce back. Something fires toward them, he makes her hide down behind the TARDIS as the energy passes. It was Helix Energy. She starts to whimper and prattle but he yells at her to stop and tosses her into the doors. The TARDIS vanishes as something sinister laughs.

15th Century, San Martino, Italy, about 1470 to 1482: Renaissance nobleman Count Federico sends Captain Rossini's guards to set a peasant's haycart on fire. One peasant is stabbed with a sword by a tree. Another is hit. And another is killed. The women run. Federico tells the Captain to leave a few alive to tell others how insurrection is dealt with.

A death knell rings. In a palace bedroom, Giuliano, a young nobleman and his redheaded friend, Marco see as a priest gives last rites to Giuliano's father, a just and noble ruler. Giuliano asks soothsayer Hieronymous how he predicted the exact day and hour of his father's death. Other young men are present. Hieronymous uses astrology mumbo jumbo to explain himself: when Mars is in the conjunction with Saturn in the House of the Ram and the room is full grown, death comes to great ones. Giuliano does not believe this. He leaves as Giuliano's uncle Federico arrives. Giuliano thought his Uncle Federico was out enjoying some sport: killing peasants. Marco tells Giuliano, after his uncle leaves, that he is alone and support-less. Giuliano wants to rule over a land without tyranny and without lies. Marco wonders how the Duke died so suddenly, he was in good health.

Federico is impatient and tells Hieronymous he wants Giuliano dead with poison in one or two days. As summer solstice arrives, Hieronymous believes his powers are growing. He thinks he can foretell more. Federico curses this horoscope and superstition: the young new Duke will die. Federico will do the rest. He leaves Hieronymous and the later stares out the window. Something evil laughs.

In the nice, warm forest, the TARDIS appears. Sarah enjoys it and finds some oranges on a tree. The Doctor finds it was a forced landing. He didn't touch a thing. He talks to himself, "Maybe that's why I stopped using the old control room." He thinks the Helix energy forcefields distorted the coordinates. The Doctor stoops to find a fallen piece of pottery or metal ware. He thinks he is still talking to Sarah and mentions from this piece -- a small water jug, glass: Mediterranean area, late 15th century, not a very pleasant time. Sarah wanders off picking and eating oranges. She is watched by three black robed figures. When the Doctor realizes Sarah is not with him, he finds her carried by one of the black robed figures and tells the other two to stop. One comes to him and raises his hands. The Doctor flips him and tells the others to put the girl down. One does but the fallen one gets up and hits the Doctor over the head with a stone. A red ball of Helix Energy comes out of the TARDIS, opening the doors and blasting a tree. It travels on through the forest. The Doctor recovers and sees the ball of energy fly near a lake and rush at a peasant who is loading hay. It hits the man who tries to defend himself with a wooden pitchfork but he is blasted into a fleshy, skeletal heap. "Mandragora energy and I brought it here. It got into the TARDIS," the Doctor states.

In his court room, Giuliano, a man of science talks of a man in Florence that has used an arrangement of glasses in a certain order to see the Moon and the stars as large as your hand. That way they can learn more about them. Giuliano tells him perhaps the stars don't move at all, perhaps it is the Earth that moves. Federico and Hieronymous rush in where the uncle bids the soothsayer to tell his newest horoscope: the death of Giuliano. Federico tells him to remember his father. Giuliano believes his father's death has nothing to do with the stars. Federico thinks the peasants are being stirred up by spies of their enemies.

The Doctor whistles, eating an orange, as he approaches some peasants who are sitting. The men run off before they can answers as Rossini and soldiers ride up on horses. Rossini points a sword at the Doctor, asking him to produce his documents. The Doctor puts his orange on the sword point and removes a noise maker (a football rattle) from his pocket to scare the horses the soldiers are on. The Doctor pushes one off his horse and takes it. The soldiers give chase. The Doctor rides into another soldier and one from the trees leaps onto him and knocks him off the horse.

Sarah is brought before a grey haired High Priest in black robes. The man who caught Sarah found her at the noon hour on the slopes of the Hills of Sorrows--as has been foretold. Some are innocent lambs and some know they are to be sacrificed. She is to be a sacrifice to the sacred blade to the god of twin realms Moonlight and Solstice -- Demnos.

Young nobles clap as Federico wins a chess game. The Doctor is brought in and he smiles. A short gallop is good for the liver, the Doctor tells Federico of his leading his men on a merry chase. Federico asks where he comes from. "Oh around, around," the Doctor said. He threatens the Doctor with the rack. The Doctor comes forward to claim he has come to help him. Rossini wants to punish this insolent dog. The Doctor explains a wave of energy has been released and can untold damage and that he must return it to the stars. They all laugh at him. A ball of heavenly fire could consume everything in its path... it could destroy the world. Rossini thinks the fall from the horse has affected the Doctor's mind. Federico thinks the Doctor is a sorcerer. Sometimes the Doctor can tell the future. The Doctor tells him he doesn't have a future unless he listens to him. Federico warns the Doctor that if he is making sport with him, he will make sport with his body.

A curfew bell rings and people are rushing back into the town walls. A soldier prompts others inside. He takes his sword out as a red Helix ball comes at him. It hits the sword and goes up the guard's arms and kills him, leaving the body a smoking shrinking mess of clothes...

Hieronymous examines the Doctor, who thinks this is all a great waste of time. Hieronymous circles the Doctor, asking what it means when Venus is in opposition to Saturn and a great shadow passes over the Moon. The Doctor tells them it depends on whether the moon is made of cheese, on whether the cock crows three times before dawn, and 12 hens lay addled eggs. It is a school of philosophy the Doctor can teach -- "All it requires is a colourful imagination and a glib tongue." Federico calls the Doctor's tongue a mocking one and prepares the executioner's block. As the Doctor is taken away, Giuliano enters and is told by his uncle that the Doctor was a spy. Giuliano thinks him a most uncommon spy.

Sarah is made to wear a white ceremonial dress-a tabard. The High Priest comes in and tells her she is blessed. When the Moon rises over the southern obelisk, her glory will come. He gives her a drink in a golden goblet...

The Doctor raises his hand and tells the executioner to excuse him. He likes to look his best on these occasions. He uncurls his scarf and wraps it around the right leg of the man about to chop his head off and trips him. The Doctor runs, jumps on a horse and dumps the man on it off. He then rides a bit, gets off and hits the horse so it would ride off. The Doctor runs through the stone alleyways, chased by some soldiers. He passes two guards who discovered the body of the guard the Helix killed. He hides in some storeways but coming out, more guards see him and give chase with pikes. The Doctor runs through town and down and up a lot of steps.

The Brotherhood ceremony begins. Feathers or paper are thrown onto the altar. Guards chase the Doctor but the Doctor vanishes down a passageway into the underground. One guard, Giovanni, wants to follow but his partner tells him that he knows many that have gone underground into the tunnels beneath the hill and never returned. They think the Doctor might be one of the Brotherhood. They opt not to follow him.

As the Doctor skulks about, the drugged Sarah is brought onto the altar with no resistance from the girl. The Brotherhood have their faces hidden by ornate silver masks. They lay Sarah on the altar. The high priest utters Demnos's name and holds a blade high over Sarah, blessing it.

The Doctor hides as a figure in a purple robe and a grisly mask passes. The Doctor follows it to a stone wall that turns, a secret passage door. The purple figure takes the knife and moves to Sarah to plunge it down but the Doctor slides her off the bottom of the altar before the blade can hit her. He carries out but before he does, he sees the ball of energy, "The Mandragora helix has come home to roost." It roosts on the purple caped figure who utters rhetoric.

Duke Giuliano is shown the body and the body was taken to his lab. He tells the guard that the charred body -- which still has hair but green modly skin -- that this thing that killed the man at the city gates was not a fire demon. Giuliano asks Marco, who enters, what he thinks of it.

The Doctor spies some soldiers outside so he and Sarah wait on steps just inside the catacombs. The Brotherhood sect should have died out in the 3rd century. Sarah tells him she was almost sacrificed. In the temple, sub thermal recombination of ionised plasma is what happened with that energy. When they landed, they brought back part of the helix which got in the TARDIS somehow and is here. When he wonders what it is up to, Sarah jokes -- they want to take over Earth and fill it with old Roman temples. The Doctor says, "NO!" He explains they -- helix intelligences don't have physical existences and don't need Earth. The Doctor stops suddenly -- there is something behind them, he can feel it in his bones -- two pike men with pikes at each of their necks.

A shaft of pink-yellow light is in the temple. The purple figure steps into it. A voice called a Titan Voice tells it he has been chosen for rewards undreamed of. It will be the Supreme Ruler of Earth -- only he must stand in this spot. Any other mortal who does, will be destroyed. He will carry out their will on Earth. The light goes and the purple robed figure tells them it is complete... the dream of 200 years answered. He dismisses the acolytes and moves through the secret door past the high priest. On the other side, the figure takes the mask off--it is Hieronymous who talks to himself about how wonderful it will be to be the Supreme Ruler of Earth.

Sarah and the Doctor are brought to Giuliano's classical lab, the Doctor pulling Sarah to him and yelling at the soldiers to stop poking him with that pike. Giuliano apologizes for their rough treatment. Giuliano explains about his uncle, Marco tells them that some of the guards are still loyal to the Prince--Giuliano. He is Duke of San Martino. The Doctor asks about his uncle. Marco tells them the uncle murdered Giuliano's father. Giuliano is more fearful for the people and what his uncle will do to lord over them. Marco is more fearful for Giuliano -- he is next. The Doctor tells them that he and Sarah cannot help, they are just passing through. The Doctor looks at interesting plans on a table. Giuliano tells them he was present when his uncle questioned the Doctor. All knowledge, all attempt at learning would be suppressed under Federico. Giuliano knows the Doctor is a man of science. The Doctor puffs, "Oh, I do dabble a bit." Sarah smiles and makes faces, "Ohh." Giuliano shows them the body -- high ionisation when it touched human tissue to destroy it utterly. The Doctor insinuates that the guards' talk of fire demons might be close to the truth. The Doctor feels they have an awful lot of questions -- it is time they started getting some answers. It is not something to do with Hieronymous, that old fraud, the Doctor says. But something has gotten into the city...

In the halls, Rossini reports to Federico that the Doctor and Sarah have not been found. Something about that Doctor disturbs Federico greatly. A list given to Rossini by one of many loyal to Federico was prepared by the Duke's secretary shows that Giuliano has invited all the greatest scholars -- the King of Naples, the Duke of Milan, Duke of Padua, Rubenence, Seniora of Florence, and other rulers to come. These have already accepted. Federico calls Giuliano an arrogant puppy. Federico enters Hieronymous's private room and is scolded by him; he yells at Hieronymous -- in this palace he goes where he wants. Federico wants Giuliano to die tonight. If all those powerful people come here, Giuliano will gain his foothold as ruler and get more on his side. Federico wants Hieronymous to make up a fake horoscope as he did before but Hieronymous now thinks Federico should not mock this, nor does the uncle understand.

Hieronymous in the shaft of light in the temple asks for greater powers to show those who mock him and his powers. The voice tells him he has powers promised above all men but the time is not yet come. The silver maned high priest comes to him. The voices brought Hieronymous to San Martino, telling him that he was here due to his special powers. For years others scoffed at him. The old Duke tolerated him. The young Duke considers him of no consequence. Count Federico despises him and thinks him a fake--they will learn their mistake as they die. The priest looks afraid.

Giuliano and Sarah sit and eat served by a man with drink. The Doctor is standing an eating, looking out the window at first. Giuliano questions the Doctor about a wheel of fire. The Doctor finds it difficult to explain Helix Energy and sub and super thermal ionisation. Sarah thinks he is doing a terrific job. The Doctor thanks her. Sarah wonders why it is in San Martino and the 15th Century. The period between the Dark Ages and the Dawn of a New Reason. The Brotherhood provided a new power base. The helix could gain control through an ancient religion and something Sarah says makes him realize the focus point of enormous energy is the stone temple. The Doctor tells the Duke the temple must be destroyed even though it is just ruins now. Giuliano insists he go with the Doctor down the back stairs. But the Doctor must go down alone once there from the temple entrance.

Moving a back way through the court yards, down steps, the trio are seen and followed by a guard loyal to Federico. The Doctor, Sarah, and Giuliano arrive at the ruins. The Doctor goes into the underground ruin of the temple.

Rossini reports to Federico about this. The Count thinks it is excellent: he can solve both his problems in one blow: it will seem like a human sacrifice to the gods -- evil pagans who worship Demnos will be blamed.

With a long sword the Doctor nears the temple altar but a loud sound penetrates his head. He holds his face as the agonizing sound of the energy ball fills the temple... and his mind...

Sitting on a stone, Sarah throws pebbles in a small pond. She listens as Giuliano tells her a theory that he has and not only he: the world cannot be flat...suddenly they see many soldiers come out of the woods above the ruins, from all sides. The Count is with a group of four of them, "Death to Giuliano!" There are many more, some with Rossini. Swords are drawn and Giuliano, outnumbered, begins to fight the man soldiers.

Sarah is taken away by the Brother and priest, yelling, "Doctor, Doctor!" The effects of the Helix fades but as the Doctor tries to leave by three other ways, the walls come alive with energy and the Titan Voice laughs again. The Doctor leaves quietly. Outside, Giuliano faces soldier after solider, three at once, then more. The Doctor hears the sounds of battle and rushes up. Count Federico tells his men that his nephew is but one man. The Doctor arrives, "You can't count, Count." Federico tells his men he will give a gold piece to the first man who splits the sorcerer -- the Doctor. The Doctor fights soldier after soldier also, getting his sword behind one's neck and tossing him off. Giuliano is wounded but the Doctor fights off five more. The Brethren come out of the ground like rats as Rossini states. They use staffs to beat off the guards and run past the Doctor and the Duke. The Count orders them all back to the palace. The Doctor and Giuliano retreat to the entrance to the catacombs. From his pockets the Doctor uses a handkerchief to stop the shoulder wound on Giuliano. They realize Sarah is wandering around in the catacombs. Giuliano realizes the Doctor he hasn't spent all his life in books. A captain in Cleopatra's bodyguard showed the Doctor a few points. The Doctor comments that he is not sure Florence Nightingale would approve of the wound lash up he just did on the Duke's shoulder. There are some nasty tricks happening in the temple via Helix energy.

Despite the Priest's protests, Hieronymous wants to use Sarah to assist in the death of the foreign sorcerer -- the Doctor. The Priest bows to Hieronymous's command.

The Duke of Milan arrives, horns heralding his arrival. Federico kicks out the man washing his face and takes a drink, angry and bitter that the visitors are arriving. Federico will not greet the Doje, he will let the Chancellor do it. Rossini will say that Federico has been stricken. Federico wants the Duke's liver fed to the dogs before sunrise.

Giuliano stops the Doctor from going into the endless catacombs. The Doctor asks him if he is afraid, Giuliano hesitates but claims he is not. The Doctor states most people would be.

Sarah is tied up as The Priest and Hieronymous talk, both with no masks on. Hieronymous tells the priest he helped Giuliano because the young Duke might still have uses. Yet the Duke's appointment with death has already been anticipated. Hieronymous tells the Priest to have faith, calling him Druther. The temple must be guarded and not defiled in these last hours. He sends the priest to do this. Hieronymous has prepared a potion which he puts to Sarah's bound mouth -- an aroma which will hypnotize her...

With a torch he lights, the Doctor presses on with the Duke. They hear the stone wall open up but the Doctor goes through.

Hieronymous adds the finishing touches on his hypnotism of Sarah using a jewelled star medallion, telling her the Doctor is an evil sorcerer. He gives Sarah a long pin bodkin and it has poison the end of it. One scratch will kill the Doctor.

Rossini reports to an angry Federico. If Rossini fails him, Federico promises he will breakfast on burning coals. Rossini tells him that the Doctor and the Duke must be in the catacombs. There bat droppings have reached the height of a man--they say. The galleries could be searched for months. Federico calls Rossini a dung head. New plan: to prove that the Duke is the leader of the secret cult of Demnos.

The Doctor and Giuliano find Sarah, her eyes strange. She can't remember what has happened. They are under the palace...the leader of the cult walked this way. The Doctor thinks the Helix bringing the TARDIS here was no accident. Someone here must be sympathetic to it already. Perhaps some influence here has been here for centuries. The question is solved by walking, the Doctor says in Latin. Sarah thought they talked Italian. Sarah never thought of something before: how can she understand Giuliano's Italian when she doesn't speak it. The Doctor will explain it later.

Marco awaits in Giuliano's chambers. Guards bang on the door to open in the name of the Duke. Rossini and others come in and overpower Marco after a fight. He is held from behind and taken off.

The Doctor leads the other two... right into two soldiers but he walks back and puts his hand over Giuliano's torch and blows the fire out. They are in the palace dungeons. Giuliano's father once built a secret passage.

Hieronymous refuses to rise in Federico's presense something the Count claims that only the dead don't do -- "Only the dead fail to stand in my presense." The Count takes out a knife to kill Hieronymous so the old man gets up and apologizes -- it is, he claims, that his numbness of fear is for the Count's life. The Count has a man put on his gloves and claims Hieronymous is a fake and a fraud. He is a court astrologer and to remember that may mean he will keep his head. Hieronymous tells the Count he is in great danger -- it is written a blow will be struck in the palace against the Count. The Count tells him he can not tell the stars than he can tell his chamber pot... Before Mars sinks to rest, Hieronymous tells the Count he will fall.

In Giuliano's room, they find the room a wreck and Marco gone. The Doctor stops Giuliano from rescuing his friend. He tells the Duke there are more important things besides the Uncle and his petty ambitions. Leonardo Da Vinci and the Duke of Milan -- his patron -- are coming. If anything should happen, there might be a throwback into a new dark ages. The Doctor leaves, thinking he knows who the leader of the Brethren is. Sarah has tried twice to scratch the Doctor but missed or was foiled. The Doctor, before he leaves, tells Giuliano that he will be safe--he is not likely to miss Leonardo Da Vinci.

Rossini and Federico go to the torture room where the hot iron is being used on Marco. Federico wants the old bat Hieronymous out of the city tonight -- it appears he is moving against him. Federico goes in to the room to talk to Marco. Scarlatti, the torturer is there.

The Doctor moves through the marbled hallways. Sarah is quietly following him with the poison bodkin. He seems to know she is and hides, allowing her to follow.

Marco's shirt is ripped and he hangs by his wrists. Federico wants him, as an educated man, to cooperate. Marco will not. He will die right away. Federico wants Marco to confess Giuliano's Brethren connections but all Marco does is spit in his face. Now he will learn what suffering is.

Hieronymous throws kindling into a pot and smoke fills up. Behind it is the Doctor, who says, "Good evening." Hieronymous asks what he is. Influence comes and goes, that must be very worrying. The voices told Hieronymous that someone from the stars will join him -- is he that one. This is just stalling from Hieronymous since he spies Sarah coming up behind the Doctor with the pin ready to jab the Time Lord. The Doctor is from the stars. He looks at the mask of Demnos remarking Hieronymous's mask is predeluvian sand stone with complex circuit of base metal infused into it. Hieronymous claims he will die for defiling the sacred image of Demnos. The Doctor turns to Sarah and talks to her, "Hello, Sarah -- poison needle. Drop it. I'm your friend, remember -- your best friend." He has to grab her arm but his talk makes her snap out of the trance. She drops the pin. Claiming the curse of Demnos on him, Hieronymous attacks the Doctor with a knife but the Doctor kicks it out of his hand, warned by Sarah. The Count's men break in, Hieronymous runs out, and Sarah tries to pull one of the soldiers off the Doctor, who is beaten down.

In the halls, soldiers also grab Giuliano, who found Sarah gone when he snapped out of his musing out the window.

Rossini reports to the Count that all the prisoners are in the dungeon -- all but Hieronymous. The Duke and his trouble makers will be dead before the cock crows. Federico thinks there is nothing to stop him now.

In the dungeon, Sarah says she is trying to remember what happened but cannot. Drug induced hypnosis. Hieronymous is an old fox. The Doctor explains that he knew all this would happen: that Sarah was brainwashed to attack him. How? He has taken Sarah to some strange places before and she never asked how it was that she understood the locals and their language. It's a Time Lord's gift he allows her to share. Giuliano is thrown in. The Doctor tells him to see to Marco. The redhead tells him that the Count and Scarlatti have forced him to say that the Doctor and Giuliano are in league to revive the blasphemous cult of Demnos. He was forced to sign a confession. Giuliano calls the Count, who has come up behind him, a butcher. Rossini reports to the Count, both in the dungeon now that the Brethren are all over the city moving toward the temple.

The light in the temple is strong. Hieronymous prays to it and asks it to show itself. His hands are smoked by the energy ball and sparks. Across the light, the Priest and Hieronymous hold hands. Both soak up energy.

The Doctor tells the gloating Count that he is not interested in his political ambitions. He warns of Hieronymous--the leader of the Brethren. If he isn't stopped, there will be nothing to rule over after tonight. The Count tells a mistrusting Rossini to unchain the Doctor -- he will take the Doctor and two of Rossini's best men. If the Count is not back in the hour, Rossini knows what to do to the three hostages.

Hieronymous tells them all their enemies will perish this way. Federico has been turned to a smoking cape and ash. Hieronymous appears to point and fire at the two soldiers with the Count. Demnos is only the servant of Mandragora. Tomorrow night the prophecy will be fulfilled: when Mandragora swallows the moon, the Brethren will strike. The Doctor circles the altar with them in disguise, then slips out.

Rossini tells his guards in the dungeon that the hour is up and the prisoners are to die. Giuliano tells Rossini that if he lays one hand on his prince, then it is he who is the traitor. Marco calls an insistent Rossini filth. The guards take Giuliano down and the Doctor appears and removes the hood from his head -- asking if a brother will do since there is no priest available for the execution last rites. He tells them the Count is dead -- Hieronymous gave him a blank look. Rossini does not have any authority to give orders any more. The guards join Giuliano. Rossini, outnumbered, bows before the Duke. Marco wants Rossini taken to the block but Giuliano has him taken away for his fate to be decided later. Marco feels the evil is ended. The Doctor takes off his robes and tells Marco he is wrong. The Doctor shushes a vibrant and aggressive Marco and tells Giuliano not to go to the temple. He wants the Duke to turn the city into a fortress using carpenters, stone masons, soldiers, anyone that help build barricades. The Doctor tells Sarah he needs time to think even if the barricades aren't going to stop the Brotherhood. Sarah knows the barricades won't stop them. When Marco and Giuliano see to it, Sarah tells the Doctor she came here with him: she understands that the prophecy when Mandragora swallows the moon is not real. He contradicts her--Hieronymous told the Doctor that Mandragora swallows the Moon tomorrow night and all the other Helix energy will join the one that they accidentally brought here via the TARDIS. Giuliano orders men to the west gate. Marco tells him that the Brethren are driving everyone from town, those that refuse to leave are being destroyed by bolts of fire.

Sarah follows the Doctor around, not sure what he is saying, getting on his nerves and making him raise his voice a few times. Realizing this, he lowers his voice.

Giuliano and Marco argue about the Masque being cancelled. It will show he is weak. Giuliano thinks it too dangerous. Marco tells him he is the leader and if he falters now, he may lose everything. If others leave saying he is weak, it will be his downfall. Giuliano thinks Marco is talking sense but seeks the Doctor's advice. Marco tells him that the Doctor has been in the lab of Hieronymous since the morning and what he does there, Marco does not know.

The Doctor is looking out a telescope. He asks Sarah for the Medieval sextant -- the astrolabe. He converts to the Copernican system, compensates for error, and makes calculations, with Sarah's help in subtracting. 43 minutes and 8 seconds past 9: the lunar eclipse and astrology will become all man has left. Sarah calls it all nonsense. The Doctor snaps that is it not nonsense and tells her to remember what Hieronymous said to her: Mandragora does not conquer in the physical sense. Astral force...takes away mankind sense of purpose and the ability to shape its own destiny. It will turn them into mindless idle sheep. Giuliano and Marco rush in and see the Doctor with his head down. Sarah thinks he is only thinking, she thinks. He seems to snore a bit. Suddenly he pops up and is energetic and wants them all to listen to him. It is all or nothing...he has to risk it. By now the plasma ionisation is spread thinly among the Brethren and Hieronymous. He wants to exhaust the energy. He wants wire and a breatplate... it has been 150 years since wire was made and there must be some. Giuliano asks if he should have the Masque. Foolishly, the Doctor says Sarah will love it and asks him to save him a costume...he loves a knee's up! Sarah says a masque is just her thing and taps her nose after the Doctor leaves.

The scholars, rulers, and nobles in the Palace will be destroyed, Hieronymous tells the high Priest. There is an entrance that ten of the Brethren will go with Hieronymous to the Palace... they will provide the entertainment.

The Doctor has a man put his jacket over the breastplate. Sarah brings the Doctor's things and costumes for the Doctor to choose from. He puts on the lion mask, "Remember the French at Agincourt." Sarah tells him they lost and that the worse the situation, the worse his jokes get. Things are bad but they can only do their best and hope, the Doctor tells her.

Three masked men sit in the Palace. They are the entertainers. The Doctor wants to know if Leonardo is among this lot. When he finds out he is not, the Doctor laments that at this rate he is never going to meet Leonardo. The Doctor wants Sarah to stay at the Palace at the Masque to keep an eye on this lot... and Sarah figures it is to keep her out of trouble. He tells her she is not equipped. He also tells her, "A Time Lord's got to do what a Time Lord's got to do." If the Doctor guesses wrong, then, he tells Sarah, it isn't just dangerous, then it's fatal. Sarah snaps at him to stop giving her flip answers. He tells her if he has guessed correctly about Helix energy, then he should be able to drain it off using magnetically charged lines of energy. Leaving her, he asks her, "When have I ever guessed wrong about anything?" Sarah says, more to herself since the Doctor is out of ear range, "Lots of times..."

Temple: Hieronymous orders the Priest to tell the Brothers to surround the Palace and kill anyone who leaves. Hiding with the lion mask, which he raises first, the Doctor starts to wrap the wire.

Palace: the show goes on, acrobats do flip. Marco tells Giuliano that the Brethren are all around the palace. A flame swallower performs and also a juggler, he juggles torches. Marco thinks Hieronymous will leave soon, the palace can keep them safe inside it for a month under siege and long before that, armies of neighbouring countries will come to their aid. They have the Uncle to thank for the strong fort. Sarah in fancy dress and with umbrella asks them if they have seen the Doctor. He's been gone for ages. All this waiting not knowing what's going on, Sarah says, "It's worse than being with him." A man in a mask asks her to dance and she joins in on the Masque dancing.

Temple: the Doctor finishes driving nails into the ground and placing wire around the altar and to his breatplate, the Doctor sits on the altar and starts playing with his yo-yo. Hieronymous sneaks up behind him and tells him he has profaned the Sacred Stone. The Doctor wants him to drop the pretenses -- Hieronymous knows the truth about the Doctor -- unchecked man's curiosity might leave this Earth so the Helix has to contain mankind to his own planet before Mankind can compete with the Helix power. If the Doctor didn't bring the Helix to Earth some other traveller in space or time would have been used to. The Doctor cannot allow the Helix to interfere with Man's progress. It's part of a Time Lord's job to insist on justice for all species. Hieronymous's mask glows and he fires bolts at the Doctor which floor the Time Lord, who claims Time Lords don't die that easily. Bolt after bolt is fired, yet the Doctor keeps getting up, off his face, and asking for more. Hieronymous asks Mandragora for help as his face glow seems to lose power...

Palace: Giuliano dances with Sarah, both worried. Sarah sees the lion mask and thinks it the Doctor. She goes to it but it will not answer her. The mask comes off and it is one of the Brotherhood...face aglow. Sarah runs as the ten Brethren reveal themselves. The room glows with red energy and the Brethren start firing bolts into people. One has a ram's head. A man and woman are shot down with fire bolts. Hieronymous appears and tells the Brothers that the final sacrifice must be made in their temple. The survivors, Sarah, Marco, and Giuliano among them, are taken down to the temple for sacrifice. The eclipse begins and the ceremony starts. The energy ball comes to the Brotherhood but bolts of energy zap them down slowly and the energy seems to grow and then just vanish. One more robed figure in purple comes out and takes off its hood: the Doctor. "A case of energy squared. It puts the Mandragora back at square one." The Doctor was using Hieronymous's voice. He wants their congratulations, "I wouldn't even say no to a salami sandwich."