The Fires of Vulcan (audio story)

 was the twelfth story in Big Finish's monthly range. It was written by Steve Lyons and featured Sylvester McCoy as the Seventh Doctor and Bonnie Langford as Melanie Bush.

This was the third full story to feature the Seventh Doctor but the first audio story to feature Mel, a role which Langford last played in Children in Need presentation Dimensions in Time in 1993. This was also writer Lyons' first contribution to an audio story; he has also contributed to a number of novels and short stories.

Publisher's summary
Two thousand years ago, a cataclysmic volcanic eruption wiped the Roman city of Pompeii from the face of the Earth. It also buried the Doctor's TARDIS...

Arriving in Pompeii one day before the disaster, the Seventh Doctor and Mel find themselves separated from their ship and entangled in local politics. With time running out, they fight to escape from the shadow of Mount Vesuvius. But how can they succeed when history itself is working against them?

Part one
1980: Professor Scalini is heard talking about Pompeii and a mysterious artifact to a UNIT woman, who takes control of the artifact. The artifact is revealed to be an English police box, implying it to be the TARDIS. In the past, Mel and the Doctor meet a slave, who belongs to Eumachia, and tells them it's the 23rd of August, the day before Vesuvius erupts. The Doctor tells the slave that they are messengers of a God, Isis, to explain the TARDIS' arrival, which he witnessed. The Doctor seems to think he's going to die. They're in Pompeii in AD 79. The Doctor tells Mel they should go back to the TARDIS to avoid trouble.

They discuss graffiti and the fact that it's the festival of Augustus, as well as Vulcan's day. A young man is following them. Mel and the Doctor's clothes are anachronistic, which is drawing unwanted attention. An old man runs into them, then tells a Roman soldier that they came from Isis, as Mel told him. Meanwhile, the Doctor and Mel meet Valeria, an innkeeper, in whose inn they meet a group of gladiators playing with dice, including Murranus, and the Doctor wagers Mel against his money. Eumachia and her slave are talking, and he tells her about the TARDIS. The Doctor wins the game, giving Valeria money to buy Mel some clothes. She tells Aglae, a servant, to buy the clothes, and Mel goes with her, telling her about how brooding the Doctor is acting.

Aglae invites Mel into her room so she can change, and spies the man who was following Mel before, who is Popidious Celsinus, a councillor. Meanwhile, the Doctor loses money to Morranus in another game of dice, and they accuse each other of cheating. Morranus tries to kill the Doctor. Mel sees smoke rising from Vesuvius, and Aglae believes it to be a sign from the Gods, although Mel fears it to be the too-early start of the eruption. An earth tremor makes Morranus slip, saving the Doctor, who escapes. These earth tremors have been happening a lot recently, says Aglae, and the Doctor finds them and drags Mel away. She worries that everyone will die, but the Doctor says they can't change events.

Mel says she's ready to leave Pompeii. Morranus promises to kill the Doctor while the Doctor admits to Mel that he did cheat, and they find that the TARDIS is buried under a building that collapsed during the earth tremor. The Doctor says that in 1980, the TARDIS will be discovered in the ruins of Pompeii, and so they can't escape.

Part Two
The Doctor says he was in his fifth body in the 1980s when UNIT contacted him, saying they'd found his TARDIS in Italy, but that version of him still had his TARDIS, so he knew it was likely to be a future version's TARDIS. Now he knows this for sure. Eumachia talks to Popidious, discussing the arrival of the Doctor and Mel, and how Popidious takes credit for Isis' temple, telling him he must prove these strangers (Dr and Mel) are false messengers, lest people think Isis doesn't love him, which would cause him to lose his seat on the council. The Doctor purchases wine from Valeria, arriving back at the inn and drinking while explaining why he can't change events such as the TARDIS being buried- it would cause a paradox. Murranus has already left. Another tremor occurs as Mel and the Doctor argue, and Mel says she won't give up.

Eumachia- a priestess- slaps Aglae, and Mel tries to get Aglae to leave, but she refuses. Eumachia says she'll expose Mel's deceit. Valeria tells the Doctor an animal sacrifice will be made this afternoon to Isis, and Aglae comes to Mel, telling her that she is her friend. Aglae brings her to the sacrifice at Isis' temple, hoping Isis may help her, but Mel walks away. Celsinus runs into Mel, and Aglae says she can't deny his offer to have dinner with him, and that he can help her clear away the rubble around the TARDIS as he is a councillor. Aglae leaves. Mel and the Doctor arrive at Eumarchia's house, not Celsinus', and Mel fears it is a trap. They eat, and Eumarchia suggests that the TARDIS is a temple. The Doctor and Mel leave. Murranus buys wine from Valeria, and swears again to kill the Doctor, revealing that he was sentenced to be a Gladiator due to a crime, assuming he would be killed, and if the people of Pompeii stop liking Murranus, they won't keep voting to save him.

The Doctor resolves to have hope of escaping Pompeii, and tells Mel to leave Pompeii, in case he doesn't succeed. Mel realises that he doesn't have hope and that the Doctor is just trying to save her. Eumarchia arrives, accusing Mel of stealing her jewels, and has her arrested by Roman legionaries.

Cast

 * The Doctor - Sylvester McCoy
 * Melanie Bush - Bonnie Langford
 * Professor Scalini - Anthony Keetch
 * Captain Muriel Frost - Karen Henson
 * Tibernus / Roman Legionary - Robert Curbishley
 * Popidius Celsinus - Andy Coleman
 * Valeria Hedone - Nicky Goldie
 * Murranus - Steven Wickham
 * Eumachia - Lisa Hollander
 * Aglae - Gemma Bissix
 * Priest - Toby Longworth

The Doctor

 * During his fifth incarnation, the Doctor was contacted by UNIT, who told him that they had found his TARDIS encased in rock at Pompeii during an archaeological excavation in 1980.

Individuals

 * Mel states that she is a vegetarian. Valeria Hedone responds that she has never heard of Vegetaria.
 * Mel made a replica of Mount Vesuvius out of papier mâché while at primary school.

The Master

 * The Doctor uses his voice to compel a guard and later Popidius into handing over a key and going to sleep, a skill previously demonstrated by the Master.

Earth history

 * According to the Roman calendar, 23 August is the tenth day before the Kalends of September.

Continuity

 * An older version of the Seventh Doctor would later return to Pompeii in August 79 in the company of Ace, (PROSE: The Algebra of Ice) as would the Tenth Doctor and Donna Noble (TV: The Fires of Pompeii) and his future travelling companion Captain Jack Harkness, on multiple occasions. (TV: The Doctor Dances)
 * The Seventh Doctor is unaware that the eruption of Mount Vesuvius was triggered by his tenth incarnation in order to stop the Pyroviles. (TV: The Fires of Pompeii)