DOCTOR WHO IN DETAIL

The TARDIS materialises, apparently, in ancient Rome. Donna is sceptical when she sees an English sign until the Doctor explains about the translation circuits. Whilst the Doctor and Donna look around they are being followed. When the ground starts shaking, and a mountains starts emitting smoke the Doctor realises where they are - Pompeii, 23rd August AD79.

The woman following the Doctor and Donna returns to the sisters of the Syballine to tell the high priestess about the arrival of the blue box. When the Doctor and Donna return to the TARDIS it had been sold by a street trader, as it was on his patch, to a man called Old Caecilius. The street trader tells the Doctor where to find him, and he and Donna head off. The Doctor is trying to locate the TARDIS, but Donna wants to evacuate the city, despite the Doctor's protests.

The Reverend Mother, High Priestess of the Syballine, predicts a future of prosperity and might and an endless empire of Pompeii, disregarding what the prophecies say about the appearance of the blue box.

The Doctor and Donna arrive at Caecilius' house just in time to catch a bust as the ground shakes. Using the psychic paper the Doctor claims to be a marble inspector, and says he might need to take the 'wooden' blue box off his hands. Donna is still trying to warn people about the volcano that is about to explode - a volcano they don't know exists - yet.

Another visitor arrives at Caecilius' house - Lucius Petrus Dextrus. The Doctor is ready to leave, when Caecilius reveals an item he has made for Lucius. Caecilius' daughter, Evelina, is wary of the Doctor. Evelina knows the Doctor and Donna's names, even though he hasn't given them. Even Lucius knows about the Doctor, naming the planet Gallifrey, and Donna, naming London. The Doctor and Donna are intrigued when Lucius and Evelina start speaking of the Medusa Cascade, and saying there is something on Donna's back.

Evelina collapses, and Donna watches as the mother helps her. Donna touches Evelina's damaged arm - which is turning to stone. Meanwhile the Doctor is looking at the heated hypocaust with Caecilius. The hypocaust is heated from Vesuvius whilst Rome still uses wood-burners. Deep down the Doctor can hear a strange noise. The soothsayers, including Eveline, are consuming vapours from the hypercaust, which contain particles from Vesuvius.

The Doctor pays Caecilius' son, Quintus, to show him the way to the home of Lucius Petrus Dextrus. Inside there are more of the items similar to the one Caecilius made.

Donna tries to tell Evelina about tomorrow, and Evelina relays this to the sisterhood. The sisterhood refuses to believe Donna, who pass the new prophecy to the Reverend Mother.

In Lucius' house the Doctor re-arranges the items into an energy converter. Lucius has been given instructions how to create the converter, but does now know what the purpose is. The Doctor grabs Lucius' arm, which has turned to stone and breaks, and escapes. Lucius calls into the hypocaust, and a creature made of stone follows the Doctor back to Caecilius' house. The Doctor urges people to get water, and to stall for time asks the creature for it's name. The sisterhood arrive at take Donna as Quintus pours water on the fiery creature. The water causes the stone to cool and become brittle; the creatures crashes to the ground and breaks.

Donna is tied as the sisterhood prepares to sacrifice her, until the Doctor arrives in the Temple of Sibyl. The Doctor frees her with the sonic screwdriver. The High Priestess demands to see the Doctor. The High Priestess is an old woman almost entirely turned to stone. The Doctor demands to speak to whatever is controlling the High Priestess and learns the species - Pyrovile. The Pyrovile has been lying under the ground for thousands of years since Pyrovillia was lost, but had awoken 17 years earlier during an earthquake, and were starting to infect human bodies through the dust from Vesuvius.

The Doctor and Donna escape through one of the ducts underneath the city. The Doctor leads the way into the volcano as the Pyrovile prophecy begins to advance.

Lucius has people bring his energy converter to Vesuvius as the sun rises on the 24th August. In the heart of Vesuvious there is an alien spaceship. The Pyrovillia is using the magma to create a new species, and aim to take over the world. The Doctor has a choice: destroy Pompeii or let the world be destroyed. The Doctor and Donna use energy converter to feedback the energy, causing Vesuvius to erupts. The sisterhood suddenly get a new prophecy - Pompeii being destroyed.

The Doctor and Donna return to Caecilius' house as volcanic ash starts to fall on the city. Caecilius asks the Doctor to save him and his family, but he leaves them and disappears into the TARDIS. Donna reluctantly follows. Donna begs the Doctor to at least save one person, and he returns for Caecilius' family.