In the city of Geath there are rumours of dark, shadowy creatures that stalk the streets at night, causing the lamps to flicker and fade. There are groans and howls, too, and sightings of clawing hands that have too many fingers.

The TARDIS lands near to an olde-worlde road made of flagstones and mud. The Doctor tries, and fails, to hitch a ride in a horse-drawn cart. Rory and Amy look on skeptically, announcing their surprise that alien planets even have horses. Eventually, they decide to walk. As the afternoon progresses towards evening they stroll through the heat and arrive at the top of a hill from which they can look down on Geath. Not only is the city beautiful (red tiles, yellow stone buildings and a domed roof made of gold) but the Doctor also extols the democratic nature of its government and the fact that it has been at peace for twelve thousand years. He also tells them of the fabled hospitality of the people of Geath (though Amy is skeptical in the light of the cart driver's failure to stop for them) and is thus perplexed to find the gates of the city locked and the gatekeeper unwilling to let them in. The Doctor eventually persuades him by use of his psychic paper. Meanwhile, Amy and Rory have clambered over the walls, so eager are they to get into the city that had such a magnificent golden hall. It is then that Amy peeps into the gatekeeper's house and is astonished to see that it is filled with golden items: candlesticks, cutlery and cushions. Leaning in through the window, she can't resist reaching out to touch the gold and is astonished to find that it is both warm and wriggling.

Eventually Rory and Amy find themselves in a carriage that is taking the Doctor to meet the king. They drive down silent streets until they arrive at the golden hall. After the guards grant them admittance they walk down corridors displaying a plethora of golden ornaments. The Doctor tells them that there are three things wrong: Geath doesn't have a king; Geathians live out their lives on the streets; there is no gold on the planet.

The visitors enter a chamber full of courtiers whose glares are responded to by the Doctor's radiant smile. There is even more gold to be seen in this room. The king sits on a golden throne, raised on a dais. Beside him stands a man somberly dressed in dark robes, the only figure not swathed in gold. Before the dais a huge golden dragon is curled. Having spotted the new arrivals, the king stands and announces them as visitors from the neighbouring city of Dant. This fact seems to amuse both the king and the somber Teller beside him but, as it explains their presence in the city, the Doctor decides to go along with the story. While Amy talks with the Doctor and King Beol, Rory makes his way around the chamber, listening to the various conversations of the courtiers. They all seem to be outdoing each other in their praise of the king.

In an arcade around the chamber he finds an old woman who is both bored and bereft of gold. She invites him to sit and introduces herself as Hilthe. She says that she finds all the gold tasteless and Rory realises that it seems garish and tacky whereas a moment before he thought it amazing. At that point the crowd begin to chant the king's name and the Teller begins to tell a story (the same story every night, Hilthe tells Rory) about how Beol brought back the golden dragon from the nearby city of Sheal and would defend the city of Geath when the people of Sheal came to get it back. The story is long and involved but the audience is enraptured throughout. Even Amy is swept along by the brilliance of the Teller's performance in delivering it. Even the distracting sound of a quiet mechanical hum from the dragon fails to spoil her experience and when the Doctor asks if she can hear something she denies it as if the sound never happened.

Hilthe tells Rory that the story is always the same except that tonight the dragon was taken from Sheal whereas normally the Teller says that Beol took it from Dant. Rory asks her if the story is true but Hilthe says that all she knows is that Beol and the Teller arrived one day with a golden dragon in a cart and challenged her, as leader of the council, to a debate. Beol won; the citizens voted him as their new leader; gold began to appear everywhere and the people made Beol king. As the king leaves the chamber at the end of the tale and the courtiers file out Hilthe tells Rory that the people of the city are changing so that she barely recognises them. She hands him a small tile and tells him to find her so that she can tell him about the old days of the city.

In their suite of rooms the Doctor tells Amy and Rory to empty their pockets. He goes first and deposits golden coins and forks onto the bed. Rory adds bracelets, rings and more coins to the pile. Amy pulls out a spoon that she must have taken from the gatehouse even though she, like the other two, can't remember taking it. The Doctor plays his screwdriver over the booty and tells them that it isn't gold. In fact it is a substance called Enamour and is banned throughout the galaxy on account of the highly dangerous nature of the technology behind it. He says that he wants to take a closer look at the golden dragon and Amy is leading the way into the corridor when the howling starts.

Amy rushes into the dark corridor as lights ahead of her flicker and fade. Something is around the corner, shrieking and howling but the faster she runs the further away it gets. She enters a smallish chamber lit by a solitary lamp. The flame seems to be dragged from the lamp leaving her with a barely visible humanoid form. Its huge arm, scaled like a dragon's, reaches towards her. Amy reaches out to touch it and her hand goes right through. The giant vanishes and the lights return, showing her an empty room. She sees a big golden heap and fixes a brooch to her jacket. As she does so Rory bursts in, eager to know what happened. Puzzled, she tells him that the noise must have been the wind which also blew the lamps out.

Rory leads her and the Doctor to the side entrance of the dragon chamber. The room is in darkness apart from the glow of the dragon. The Doctor uses his screwdriver to remove a tiny piece of the dragon. He shows it to the other two and tells them that he knows they want it. That is the nature of Enamour: it bewitches people and alters minds. People want it, and then they become jealous of it until nobody trusts their neighbours or friends.

Rory tells them about Hilthe and her defeat in the elections when Beol arrived with the dragon. He shows the Doctor the tile that Hilthe gave him and the Doctor recognises it as a map showing how to find her house. He asks Rory to bring Hilthe to him. After Rory leaves the Doctor uses his screwdriver to loosen a part of the dragon and removes a curved plate. The writing on the plate tells him that the dragon was made a long time earlier by a distant civilization. The question is: why did they abandon it on this backward planet? And, where did Beol and the Teller find it?

Rory uses the map on the tile to locate Hilthe's house: easily recognised as it is the only one not slathered in Enamour. A servant leads him to Hilthe who has obviously just got out of bed to receive him: at last, an example of Geath's fabled hospitality. Rory tries to tell her that the Enamour can alter people's minds but she finds this unlikely. Abruptly he notices a gold ring in his hand but he has no memory of where and when he picked it up. The ring begins to twist, unstoppably, in his hand. Hilthe takes it from him and immediately collapses in pain. As Rory tries to help her he is pushed away by an invisible force. Hilthe is suddenly bathed in light that seems to come from within her. She speaks in a melodic voice and announces that she is the Herald who speaks on behalf of her masters, the Bright Nobles of Feond. She offers a reward for the return of the dragon. Rory replies that it isn't there on the planet and the Herald abruptly sighs and vanishes. Hilthe, returned to normal, says that she wants to meet the Doctor.

The Teller emerges from the shadows to ask why visitors from Dant are in the council chamber. The Doctor tells him that he must be well aware that they are not from Dant. As the Teller fondles the dragon his voice seems to take on greater power and resonance. He tells them that Beol is a good king who will protect the people and that they know this and love him. The Doctor's curt response - that there should not be a king - seems to make the Teller and the dragon angry. The Doctor calls him a liar. Hilthe and Rory enter. The old woman is furious that two men are speaking so uncouthly in the council chamber. The Doctor says that he can tell a tale that will turn their worlds upside down. He takes a dragon scale in his hand as he speaks and the Teller is suddenly in awe of him. Hilthe watches this with puzzlement while the Doctor explains that it is the dragon that makes the Enamour and the Enamour makes the people jealous and afraid. Amy sees the weakness in the Teller's face and suddenly recalls the creature she chased in the darkness. After she has told the Doctor about it he wonders whether it is a scout searching for the dragon. He says that if it is, then a Herald will appear to demand the return of the dragon. Hilthe produces the ring and says that such a thing has already happened. She asks if the Herald is really alive or just an echo of the dragon's former owners speaking down the long years. She decides to put the ring on again to find out.

The Herald's return is even more impressive as her voice rings around the chamber. The Doctor realises that this isn't a recording but a live manifestation. When she demands the return of the dragon he asks how she can prove that it originally belonged to her masters. He points out that Enamour is banned across the universe but she responds that her masters will take care of it once it has been retrieved. He says that he will deal with it himself but not before she begins to warn him that her enemies are close. She adds that the dragon was hidden during a war after which the Bright Nobles lost their homes. Their enemies were motivated by envy, she claims. A figure of darkness materialises behind the throne and grows rapidly until it looms over them. The Herald flickers and fades but then rallies and begins to grow. She sends shock waves at the dark figure which reaches for the Herald who fades and vanishes. There is a shriek and Hilthe falls to the floor, dropping the ring. Rory rushes to her aid while the others look at the dark shape towering over them. It speaks slowly saying that it is a representative of the Regulatory Board and is claiming the Enamour under Clause 9.4b (subsection 12.2) of the Psycho-Manipulatory Metals Act. It gives them ten standard time units to hand back the metal or 'reasonable force' will be used. The Doctor realises that the large shape is a projection but the two spaceships in the form of dragons that are crossing the sky are real. To his consternation he identifies them as gunships.

He turns to the dark figure of the Regulator in a rage and announces that its people are threatening a pre-industrial pacifist planet. He queries whether the gunships constitute reasonable force. Next, he tells Amy to go after the Teller who has fled the hall. She follows him through the confusion of the streets as people emerge in panic to look at the dragons in the sky. They are blaming Dant for this action despite the Teller stopping his escape to tell them otherwise.

Back in the hall the Doctor is informing Hilthe that the dragons are the weapons of the Regulators. As he does so, the ships open fire, blasting the trees beyond the river. The Regulator says that nobody has been harmed and this is merely a warning. It then disappears. The Doctor spits with fury at the actions of 'bureaucrats'. Hilthe demands to know what is going on and why her city is being destroyed. Recapping what she has learned, Hilthe says that the dragon was made long before her people were born and it was abandoned during a war. Since the dragon was found and her people began to work its metal it has sent a signal to its makers but that signal has also been followed by their enemies. The choice is whether to give the dragon to the Herald, as the rightful owner, or submit to the threats of the Regulators. She asks whether the Doctor can use Enamour to make weapons to defend the city. He says he won't allow such a thing because it would lead to their destruction and Hilthe would become the Queen of Ruin. She thinks for a while before admitting the wisdom of his words. Just then, the dragon wakes.

In the street, the Teller is accosted by a group of angry men who accuse him of bringing this danger upon them. Amy steps in to protect him. He thanks her before running away up some steps before doubling back and re-entering the council chamber through a side door. Amy follows. He takes a winding route through corridors that arrive in private chambers where Beol enters in golden armour. He says that he has been ordering the defence of the city against the dragons. Beol says he will protect the Teller just as the Teller has looked after him through their lives. Watching from a doorway Amy realises that these two men are brothers. The Teller tries, in vain, to explain that the dragons are not from their world but Beol cannot comprehend this idea and still blames Dant for the attack. He orders the three spies from Dant to be arrested.

The dragon lifts its wings. The Doctor steps forward and reaches in to pull out a piece of equipment which he says is an emotional amplifier, the source of Beol's victory over Hilthe in the elections. He says that the Regulators are using similar devices to frighten the population. He pulls out another device: a small box with a tiny satellite dish. He uses it to project pictures onto the dome of the chamber. The images show the golden empire of the Bright Nobles of Feond as it is destroyed from within by rebels in a civil war that spreads across star systems and centuries. At the end, the last survivors escape into space in lifeboats with their few remaining possessions. Having seen these terrible things, Hilthe asks the Doctor what action he recommends now. He says his first course of action is to get the dragon out into the main square but before he can do anything Beol strides in.

The King declares that he will do anything in his power to protect the city. When the Doctor indicates the dragon gunships Beol ignores him and tells his knights to lock up the newcomers. Hilthe tries to intervene until Beol accuses the Doctor of being a spy from Dant. When Hilthe hears that the Doctor used credentials from Dant to enter the city her sympathy fades and is replaced by mistrust.

From the doorway, Amy watches her friends being led away to the cells. She follows Hilthe back to her house. On the way, the old lady detects her presence and tells Amy to hand herself in. Amy argues that she only wants to help and Hilthe agrees to listen to her pleas at her house. Once inside, however, Amy realises that she is in a trap: the doors and windows are locked and guards are soon at the door. She escapes through the servants' quarters and onto the rooftops. After a hair-raising chase she is caught and soon finds herself locked up with the Doctor and Rory.

The screwdriver has no effect on the door but the three are eventually released by the Teller. Concerned by all he has seen and heard, he alone has the wit to turn to the Doctor for help. He doesn't want his brother to die and, since Amy came to his aid earlier, he thinks the newcomers are the best hope to avoid mass destruction. He fills them in on his history: he and Beol lived out in the Vale of Evesh and worked as farmers; when the cities of Sheal and Geath renegotiated their borders their farm was split down the middle; their objections resulted in Beol being beaten by Geathian goons; the brothers fled and travelled for a year until they found the dragon; once they discovered its power they decided to return to Geath to extract their revenge (with Sheal being the next city on their list). Having finally unburdened himself of this story he turns to the Doctor for advice. The Doctor tells him that they need to get all of the Enamour into the square as soon as possible. In order to achieve this, he tells Rory and the Teller to take the tiny satellite dish and use it to transmit the Teller's voice and image. The Teller's face will appear on every Enamour surface and his voice will be heard by everyone nearby. The Doctor says the Teller needs to tell the story of his life to persuade everyone to give up their Enamour.

Rory and the Teller set off on their mission while the Doctor and Amy make their way up to the hall to steal the dragon. Rory sets the device down on the steps above the main plaza and points the dish at the Teller who begins his call for the citizens to bring out their Enamour. Soon, people begin to leave their golden goods and a small pile starts to accumulate but the Regulator's appearance in the plaza sends others scuttling for safety. Beol appears on a horse and charges the apparition which promptly vanishes. Having seen their foe vanquished the crowd returns, no longer bearing Enamour, to chant Beol's name. Frustrated, Rory wonders what to do next. He decides that Hilthe will be more persuasive than the Teller.

Beol and four of his knights apprehend the Doctor and Amy in the hall. Amy begins to emit light as her body is taken over by the Herald. She demands the Enamour on pain of the destruction of the world. The Doctor shouts at Beol that this, not Dant, is the true enemy. He sets the small black box on the floor and a Regulator emerges. It attacks the Herald who fires out rings of energy, killing two of the knights in the crossfire. Amy tries to fight back against the Herald and calls for the Doctor to switch off the Regulator, which he does. The Herald continues to punish Amy, singing a song of unending sorrow, but this only makes Amy more determined to fight more. The Herald departs and Beol rushes over to Amy, praising her bravery. The Doctor asks what she saw of the Herald's worlds. She replies that Enamour was used to create a craving that kept people in thrall in an unchanging life that stretched endlessly. What started as security ended as a golden hell. She asks the Doctor if he feels sorry for the Herald because he seems reluctant to blame her for her part in these actions. He says that the Bright Nobles are the true villains. Beol, shaken by the deaths of his knights, agrees that the Enamour must go.

Rory and the Teller break into Hilthe's house. At first she thinks that they mean to kill her until the Teller explains why he came to Geath and the contempt he feels for the city. Then he says they must set aside their differences in order to save everybody on the planet. Persuaded, she agrees to help them and they return to the plaza. This time Hilthe makes the broadcast and her words bring a steady stream of citizens carrying the metal. By the time Amy and the Doctor arrive there is a huge pile of it and teams of people are stripping Enamour from the domed roof of the hall. Beol and his men carry out the bodies of the two murdered knights. The king throws his golden armour onto the pile which is now massive. The Regulator returns and towers over them.

One of the king's knights horses, terrified by the booming voice and immense size of the Regulator, bolts through the crowd. Its young rider is thrown off and crashes into a pillar, a blow that kills her instantly. Furious, the Doctor rounds on the Regulator and demands to know if this is their plan, to murder more and more people until they get what they want. Abruptly, the Regulator shrinks to normal humanoid size and shape. She is clearly weeping and protests that she meant no harm. She says that her action was prompted by haste: the metal has to be removed before the Herald seizes it. The Doctor says that she only needed to ask, there was no need for fear tactics. She responds that if the Doctor had lived all of his life with Enamour there would be no need to explain to him. Amy says that she understands and that she trusts the Regulator with the Enamour even more than she would the Doctor. He demands that the people be protected from the wrath of the Herald the regulator says that the Doctor and Amy should come aboard their ship to ask for military force to be deployed (that, it seems, is not in her job description). The Doctor says that Hilthe must accompany them.

The interior of the ship resembles nothing so much as an open plan office peopled by civil servants. The ship is apparently called Department Four. The chief sub-director, a woman called Anwa, greets them. She apologises for the deaths that they have caused and says that the policy of frightening worlds into submission will be reconsidered. Hilthe negotiates a treaty where Geath becomes allies with the Reconstruction and falls under their protection. The Doctor warns that when the Herald arrives she will not come as a projection as she did before, but will manifest her true self. Anwa says that the Herald will be fought and detained for rehabilitation. The Doctor asks if he can speak to the Herald first, before any fighting begins. The Herald needs to know that the Bright Nobles are all dead and she is alone. Anwa agrees and says that Camba will be at his back if he should need her help (Camba is the girl who materialised in the plaza).

Camba and the three visitors beam back to the plaza. Camba hides in the shadows while Hilthe puts on the ring and summons the Herald. The Herald arrives in front of them and the Doctor tries to explain to her that her masters are dead. She turns on him and Camba leaps to his rescue. The two combatants grow to huge size and there is a long battle that lasts until dawn, at which point Camba is victorious. The Herald is transported to the ship. Camba bows to Hilthe and fades away, too.

By daylight the city of Geath is revealed as an intricate and beautiful place. The dead knights are honoured and buried. Beol and Hilthe lead the funeral procession, attended from a distance by Anwa and Camba. After the funeral a deputation from Dant arrives to ask about the strange lights in the sky the night before. Beol receives them as temporary leader but insists that Hilthe join him in speaking to the delegation. The Doctor is sure that they will announce that it is time for some electoral reform.