Mickey summons the Doctor and Rose to the British Natural History Museum and along with Jackie they visit the Roman gallery where the young man shows him his discovery; a statue of Rose, posing as the goddess Fortuna from two thousand years ago. As they examine it they discover it has the same jewellery as Rose yet only one arm; and the two time travellers soon realise that this means they are destined for a visit to ancient Rome.

Stepping outside Mickey explains to Rose that he has been volunteering to take guided tours around the museum but asks her not to tell the Doctor, who is already saying his goodbyes in preparation to leave.

Some time later, after Rose has abandoned the idea of wearing a bed sheet as a make-shift toga and put on a genuine Roman dress from the TARDIS wardrobe, the TARDIS lands in ancient Rome and she and the Doctor, decked out in a real toga, step outside. Despite being rather unimpressed with the general hygiene of the city around them the two travellers are sprung to action when they see an old man being mugged.

After Rose wards off the attackers by hitting them with large pottery urns, the Doctor helps the old man to his feet, who introduces himself as Gracilis and explains he is on an important search mission. As the three of them begin to walk away the Doctor asks the date and he replies, telling him it is the Ides of March, much to Rose’s amusement. The two travellers see that he is very weak and take him to a nearby café where he explains that he is looking for his lost son Optatus.

The owner of the café overhears their conversation overhears them and tells Gracilis that he should consult a local girl, who has the ability to predict the future with much accuracy, she has even predicted the fall of the empire. The old man is keen to consult her and as he sets off the Doctor and Rose follow, keen to find out more.

When they arrive on the small estate of houses Gracilis pays the proprietor of one of the buildings to see the young girl who turns out to be a slave. As Gracilis talks of his lost son the young girl, called Vanessa, begins to list a series of complicated equations that intrigue the Doctor but when Rose thinks about it she realises the girl is bluffing, simply scrawling down the numbers in an attempt to think of something to say.

The Doctor drops the hint that perhaps Vanessa needs to be at the last place Optatus was seen in, in order to make a proper guess at where he is now but her owner refuses, claiming he would loose business. Gracilis manages to convince the man to sell her to him and soon the four of them are on their way to Gracilis’ villa in a horse and cart.

Rose tries to ask Vanessa about herself and learns that she is only sixteen years old, but when she asks how she got into astrology the girl starts to cry. The time traveller wonders what is making the girl so scared and the next morning, after a stop at a way station for the night, she begins to question her more but fails to find out more.

The Doctor meanwhile has calculated the date as 120 AD, and whilst he consults with Rose the group finally arrive at the villa. Marcia, Gracilis’ wife welcomes them and whilst her husband tells her about Vanessa the others go up to bed.

The next day Rose finds the Doctor sitting under a tree, thinking, and after they amuse themselves with banter about the Doctor being the next Hercule Poirot, they are taken by one of the servants to the villa’s grove, where Gracilis introduces them to Ursus, a master sculptor. He unveils a statue of the missing Optatus and as Marcia longingly hugs it, she comments that now the others can find the real human.

Once left alone with Ursus the time travellers ask him about his work but he remains very secretive, not allowing them to visit his workshop. He also denies knowing much of Optatus, before taking the opportunity to ask Rose to pose for a statue of a goddess he is due to start work on.

Some time later, in the villa grounds, the travellers discuss the sculptor before pondering if Vanessa really can see into the future, the Doctor disbanding Rose’s firm disbelief by explaining that Vanessa once talked of Hadrian’s Wall, despite the fact he has not been built. A while after they separate, the Doctor sets off to talk to more people about Optatus whilst Rose talks with Marcia and Vanessa.

She talks to them about Ursus and Marcia comments how clumsy he was as a child, yet he suddenly became an expert at sculpture. She tells them she met him at the Festival of Fortuna, the name of which makes Vanessa shiver and reminds Rose of the name of the statue she saw in the museum.

She goes on to talk about modelling for Ursus before taking Vanessa to meet the Doctor, managing to get her to admit her ‘predictions’ are all faked. She promises to return her home once Optatus is found but the young girl bursts into tears, explaining she hasn’t a home.

The Doctor joins them and explains that Optatus was last seen visiting Ursus’ studio when the statues was still in the planning stages, however when the boy disappeared it was apparently almost finished, despite the fact sculptures can take months to complete. After contemplating life as a sculptor he tells the others that they must get into Ursus’ studio and find out his working habits.

The two travellers leave Vanessa to her thoughts whilst they go on, Rose explaining Vanessa lack of foresight and the two of them contemplating the concept of slavery, before the Doctor sees Ursus walking in the grounds, meaning his workshop is empty. He runs with Rose to the workshop and pick the lock of the door, before stepping inside where they find a young man called Tiro, who is also acting as a model. As he talks to Rose about posing the Doctor notes how Ursus has no stone to work on.

Soon Ursus returns and yells at them for trespassing before telling Rose to return the next day for her sitting but disallows the Doctor to come with her. The Time Lord asks where the stone for the statues is and the sculptor tells him it is to be delivered. After accusing the intruder as a rival sculptor and ignoring his prattlings about the pristine condition of the workshop, coupled with the gloves he wears whilst working he throws the two strangers out, where upon they decide to go to dinner.

After struggling to get used to the strange seating positions Rose begins to examine the food that is being served at the banquet, also having to accustom herself to not having a knife and fork. She notes that Vanessa is nowhere to be seen and after the meal she leaves to find her in the grove, where they talk about upholding Vanessa’s disguise and Rose’s early call for posing in the morning.

Vanessa offers to wake her on time and as Rose contemplates how in her time the Roman Empire would be dust, with only artefacts like her statue, Vanessa prepares to enter the house and they walk off together.

The next morning the two girls make their way to Ursus’ studio but the sculptor tells the would be prophet to leave he and his model alone. Once she has gone he gives Rose a goblet of wine which, when drunk begins to make her feel giddy. As she begins to pass out Ursus places a spear in her hand, like the one her statue was carrying and as she realises her time may be up she watches as the modeller uncovers another statue, the completed model of Tiro he had never even stated the day before.

With little success the Doctor has been investigating and comes to the conclusion only Ursus knows where Optatus can be found. He decides to go and visit Rose and when he arrives at Ursus’ studio finds a cart pulling way carrying the completed statue of Tiro posing as the god Mercury. As he thinks he suddenly thinks of how Ursus could have made such lifelike statues so quickly, and he begins to run.

In the studio Ursus talks to the paralysed Rose, explaining that he prayed to his goddess for the ability to sculpt despite his stumpy fingers and one day his prayers were answered. As he talks Rose remembers the man with Petrifold Regression from the hospital on New Earth, then passes out.

The Doctor finds Ursus loading another statue onto a cart but before he can see it he is knocked out by Vanessa, who explains when he comes round a while later that she was actually aiming for Ursus but missed. She explains that she has no idea where Rose has been taken but the Doctor explodes at her, accusing her of lying before going on to tell her to explain how; despite the fact she has a non-Roman name, knows of the un-built Hadrian’s Wall and has the ability to calculate a mathematical formula from the twenty fourth century, is thousands of years in her own past. He demands to know what has happened to Rose but instead of answering she pulls a weapon on him and threatens to shoot if he does not let her go.

The Doctor manages to take the device, which he discovers is a vid-cast remote control. Vanessa breaks down and explains how scared she has been since she arrived in Rome after leaving her home on Earth in 2375. The Doctor sees her distress and does not ask how she arrived and instead they go to Ursus’ workshop where Rose is nowhere to be seen.

Vanessa admits the statue Ursus was taking away was of Rose and the Doctor realises that it is not a statue; it is Rose having been turned to stone, it is Rose standing in the British Museum. He vows to find her then returns to his room to fetch his Sonic Screwdriver, and when he arrives find it inside a small drawstring punch Rose has made him as a present.

He sprints outside with Vanessa, out of the villa and finds a fork in the road. After guessing that Rose will have been taken to Rome he takes the path he believes to the correct route whilst Vanessa takes the other, each planning to return to the villa at nightfall. Despite his search along the road the Time Lord finds no trace of Rose and is forced to head back where he finds no trace of Vanessa but ignores it and asks Gracilis to help him get to Rome.

The two men travel by donkey and stop for the night in a way station where they let the mules rest. The Doctor asks the proprietor if there is a spare horse for him to ride on with but he tells him there aren’t. However, when a soldier named Rufus arrives the Doctor takes the opportunity to liberate the horse set aside for his use and is soon no more than a speck in the distance of the horizon.

After arriving in Rome and embarking on a fruitless search for Rose’s statue, the Doctor finds himself in a shrine to Fortuna, the goddess Rose’s statue was modelled on. The statue inside is not the one he is looking for but as he turns to leave a disembodied voice addresses him and a phial of liquid rolls along the floor towards him, which the voice tells him will bring the statues back to life. He tries to find the source of the voice but is interrupted when Gracilis enters attempting to warn him of something.

Suddenly Rufus enters and his band of soldiers drag the Doctor away to the arena, but on his way out of the shrine he drops the phial, the one cure. He ponders his dilemma as he is dragged away and then wonders why the voice was speaking through an alien vocoder.

The Doctor is taken to a dungeon in an Amphitheatre where two guards, Flaccus and Thermus, lock him in after taking away his belt pouch, containing the sonic screwdriver. He sits and introduces himself to his fellow depressed prisoners, who explain they will be put in the arena the next day. The Doctor comes to name them Ringo, John, Paul and George and he listens as the four of them talk about violent events they have seen in the arena.

Throughout the night the Doctor appeals to guards for help but makes no ground and the next day, as the crowd’s cheers ring out the four prisoners explain to their new comrade that the first event is now over, after the clear up of the bodies it is their turn in the arena…

Thermus enters and tells the Doctor that an old man, Gracilis, has appealed for his freedom and now it has been granted he is led away. He passes the guards quarters and takes the opportunity to retrieve the sonic screwdriver, before being shown the way out, up a ramp. He walks up and the door closes behind him. He looks around and realises he has been tricked; he is standing in the arena.

A series of trapdoors are opened and starved creatures such as lions, tigers and bears are released. The Doctor bows to the crowd then dispatches the lion with the sonic screwdriver, lulling it to sleep. Next comes the bear and the Doctor scrambles up a tree for safety, dropping the sonic screwdriver. The bear prepares to climb the tree and the Time Lord jumps down. Clinging to the creature’s neck.

As the mighty beast prepares to roll on it’s back to unseat it’s rider the Doctor leaps and grabs the sonic screwdriver, firing it at the roaring bear which sulks away. Suddenly two of the animal trainers enter, armed with flaming torches and tridents. They torment a nearby tiger and it runs for the Doctor, who jumps over its head and runs off, leaving the trainers to be devoured. The Time Lord, now holding the trident, realises there are more animals to come and that he must get out, but nobody has ever escaped from the arena…

Ringo, Paul, John and George are brought out and tied on stakes with raw meet left at their feet. The Doctor rushes forward and begins to cut them free with the trident. As the men help to free each other as well as other prisoners. Suddenly a group of leopards are released, followed by a group of guards who are dispatched by the prisoners. Flaccus and Thermus are left and they run, tripping over the sleeping lion and waking it up.

The Doctor leaves them to their fate and uses the trident to pole-vault over the arena wall, into the stands. Brandishing a liberated sword he takes two senators togas then uses them as a rope to let the others scale up the wall. Many do so and arm themselves with swords, as the now present Gracilis manages to warn the Doctor that Rufus is about to attack. The Time Lord avoids being hit by an arrow and upon Rufus’ second attack the magistrate is killed by George. The remaining men escape the arena and together they run for freedom, out onto the streets.

Outside the Time Lord marvels at his escape then meets Gracilis and together they prepare to leave, the Doctor using Gracilis’ cloak as a disguise. They arrive back at the shrine of Fortuna where the Doctor dropped the phial, only for Gracilis to reveal he picked it up after his friend’s capture. They prepare to find Rose’s statue and a man at the shrine tells them a new statue by Ursus is about to be unveiled in the forum. The two friends rush there, the Doctor still contemplating the familiarity of the ghostly voice that talked to him before his capture. They soon arrive at the forum but the Doctor’s joy is short-lived. The new statue is not of Fortuna, it is of Mercury. This is not Rose’s statue, it is the slave Tiro’s.

The Doctor’s heart sinks but he realises he has work to do. He takes the phial of liquid and spills a drop of it on Tiro’s statue. Slowly but surely the stone becomes skin again, and Tiro comes to life much to many spectators surprise. The Doctor covers Gracilis and Tiro’s departure by performing magic tricks with a coin, and then moves to join, them telling them they must cure all of the statues before going back to the villa and saving Optatus.

As the day progresses the Doctor and Gracilis embark on their journey to save the trapped slaves, and after Gracilis promises the Doctor that he will take care of the free slaves they move to find the last statue. However when they locate it they find it under heavy guard due to the disappearance of the other statues. The Doctor sneaks past as Gracilis distracts the soldiers. The Doctor uses some of the last remaining solution to awaken the young girl but is seen by a guard. He manages to convince the guard he has not stolen the missing statue and with Gracilis’ help is able to walk away unharmed with the liberated slave.

After the Gracilis arranges transport for the would-be statues, he and the Doctor prepare to return to the villa, picking up the TARDIS on the way. They arrive some time after and the Doctor uses one of the last drops to revive Optatus, allowing him to fall into the clutches of his father’s embracing arms. The Doctor finds that there has been no word from Ursus or Vanessa since he last saw her, and as Gracilis and his family celebrate, the Doctor finally realises exactly where he can find Rose…

He arrives back at the British Museum where Mickey welcomes him. He is forced to admit that the statue before them is Rose and Mickey breaks down, almost in tears as he realises his old girlfriend might be dead. As he laments that she was always to good for him and how he always knew she would leave him eventually, the Doctor admits there is a way to save her.

When the statue is left alone they return to it where upon the Doctor pours the remaining liquid over the stone figurine, but no change occurs. As he and Mickey realise it is too late to change her back the Time Lord realises the statue is not really the one he is looking for; whereas it is wearing two earrings the real Rose was only wearing one after she saw the statue for the first time in the British museum and took one off to compare t to her counterpart.

The Doctor discovers there is a very small amount of liquid left and begins to realise where the other state might of came from and with a little help from Mickey he is soon on his way back to Rome.

It is a few days before he rescued the rest of the statues and the Doctor manages to revive Rose before explaining she is dressed not as Fortuna but as Minerva, the goddess of art. Vanessa arrives and finally explains the events leading up to her arrival in Rome:

Her father was a scientist experimenting with Artificial Reality. She had been at home watching a vidcast on Ancient Rome when the power cut out and she found a box containing what she presumed was the device her father was working on. She did not look at it but instead received a phone call from her friend during which she mentioned how she wished she were in ancient Rome. Everything went dark and the next thing she knew she was in Rome.

The Doctor decides it is time to find Ursus, whom he followed in order to find Rose. He begins to trace the footsteps the sculptor would have made on his way around. The three friends arrive at a run down temple where they find Ursus worshipping a woman dressed as Minerva, who Rose realises by the light in the woman’s eyes is a real goddess. As the sculptor reaches to sacrifice a lamb to his worship Rose rushes to stop him but is too late as she is thrown into slow motion. The deed is done and soon Minerva has absorbed the spilt blood, and the body of the lamb…

The Doctor gets Ursus to admit that it was the goddess Minerva who gave him the ability to make statues, after he began to give offerings to her. Rose begins to attack him by asking why he sacrificed so many people for his so-called art. The Doctor meanwhile begins to dismiss the idea of a real roman goddess; he has seen many things in his time such as abominable snowmen, werewolves, demons and vampires but never could a goddess be real.

He suddenly comes to realise what the goddess really is and wishes to see it in its true form. There is a sound like thunder and the goddess transforms into a small platypus dragon-like creature sitting in a box. Ursus lunges at the Time Lord with his knife but only manages to turn the Time Lord and Vanessa into stone, before falling on the knife and killing himself.

Rose cries over the Doctor and wishes he had never come to Rome. There is another sound like lightening and then he is gone, leaving Rose to think that something is missing from the room but not being able to think what…

Rose strives to remember how she ended up in Rome and decides she must have been hijacked by aliens. She wishes she knew how she arrived and sure enough after the dragon-like creature in the box replies it all comes flooding back to her and she realises the Doctor has gone.

She reels in horror as Ursus’ body is absorbed by the dragon creature, much like the incident with the lamb. She calms herself then asks the creature where the Doctor is but it denies there was ever a doctor present. Upon the young travellers’ request it explains it is a Genetically Engineered Neutral Imagination Engine, or GENIE for short. It is an invention of Vanessa’s fathers and is capable of granting wishes.

Rose realises that it was the GENIE that brought Vanessa to Rome and also gave Ursus his special power but after she asks it tells he that it cannot bring the Doctor back by reversing her previous wish. It does however refill the phial of liquid that the Doctor acquired and Rose uses it to bring Vanessa back to life. She then begins to think about using the GENIE to get Vanessa back home but it explains to do so it needs more energy, 1,718,902 times more than is obtained by consuming one dead human body.

Rose and Vanessa decide they must go back to Gracilis’ villa and after Rose wishes that the GENIE take on the appearance of a monkey as soon as any Romans are around the two girls take the creature outside to Ursus’ cart and prepare to leave. They arrive some time later to find Marcia waiting for them and are invited to a party. Rose realises that if Marcia recognises her despite the fact the Doctor supposedly never arrived; technically she should not be present, time must be trying to heal the paradox that has been created.

During the party, as Rose wonders what to do next events take a terrible turn as the GENIE, held in its box by Vanessa, begins to grant the many wishes of the other party-goers. Soon people are being moved across the room or disappearing all together, people change appearance and gain possessions and suddenly one of the young men present is transformed into an Emperor.

Rose denies his status and as the brainwashed masses begin to turn on her she calls out with one last hope to the GENIE, wishing that she and Vanessa were somewhere safe. There is a sound like thunder and everything disappears.

Rose and Vanessa find themselves in a white void where nothing else can be seen. The distortion of perception means Vanessa soon gets lost and once Rose manages to find the GENIE she has time to figure out exactly why the creature can sends her and Vanessa between realities yet cannot send Vanessa home.

She realises the GENIE does not alter reality. It does not introduce new matter or take things away; it merely alters people’s perception of the matter concerned in the wish they make. The Doctor is not really gone; the GENIE has merely altered her own perception so that she cannot see him. She wishes that she and Vanessa were back in Rome and that their perceptions of reality had not been changed.

Soon enough she is back in the shrine with the petrified Doctor before her. She takes out the phial of liquid and uses some of it to bring her friend back to life and soon enough they are together again. The Doctor congratulates her on discovering the truth but his friend is not finished yet. She gets the GENIE to undo all of the wishes back at the party then asks why the creature once before told her it couldn’t undo her wish to bring the Doctor back. The Time Lord answers her question, telling her the creature didn’t want to because it was afraid of him.

The Doctor explains the GENIE was afraid of him because it knew the Doctor knew that GENIES would do mankind no good, they would simply use them to smite each other and cause disrupt and agony for each other. The human race saw this and were forced to create a massive paradox where they took the very first GENIE back in time to stop it’s own creation, but to do this they needed the energy of the sun to do this and the creature died as a result.

Vanessa’s GENIE is the same GENIE that was taken back in time but at a point before the incident occurred and as a result if it were to return to Earth the entire planet would become over-run once more. The Doctor explains that although the GENIE cannot go home Vanessa can. He and Rose prepare to take her home in the TARDIS but first there is something else to do.

The Doctor takes them to the shrine where he first found the phial of liquid and heard the goddess Fortuna speak to him. After regaling his companion as to how he once had the luck to avoid getting married to an elephant, the Doctor pushes her out into the shrine where she sees the past version of himself inspecting the statue of Fortuna. She rolls to him the phial of liquid, talking to him via a vocoder but panics when the Doctor drops the phial and is abducted. Gracilis enters but nearly leaves without taking the phial but Rose uses the GENIE to make sure he returns and picks it up, so as to hand it to the Doctor later after his escape from the arena.

Some time later the Doctor and Rose drop Vanessa home and the Time Lord warns her to make sure her father never develops another GENIE and as soon as she is settled they take off again, wondering what to do with the creature they still have onboard. Rose decides to grant the GENIE freedom and wishes that it had the ability to not be enslaved, that it could only grant wishes when it wanted to. She then wishes it was somewhere it could be at peace and with a sound like thunder the creature is gone.

Rose realises there is still something left to do, there is now no statue left to be put in the museum in two thousand years time but amidst her panic the Doctor takes her into another room of the ship where there stands another statue of her, one he has sculpted himself. He explains that when he went back to the museum and met Mickey they picked up the statue there and found the Doctor’s Gallifreyan signature underneath. He then went back to the Renascence and made the statue with the guidance of Michelangelo before returning to Rome to follow Ursus and save Rose.

They take the statue back to Gracilis’ villa where it takes the place of the new revived statue of Ursus and once it is in place Gracilis tells them he will honour them all of his life for the deeds they have done. Rose makes him promise he will not offer them sacrifices and he heartily agrees.

Soon history has taken its true course again; Jackie has a photo of the statue sellotaped to the cupboard wall, Mickey is still taking children to see the figure in his spare time and in the distant future Vanessa sits and wonders if her father will create another GENIE in order to end her boredom…