The Fires of Vulcan ( audio story ) 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 ? Plot . An archaeological dig in Italy has turned up something strange — so strange , in fact , that UNIT , under the command of Captain Muriel Frost , has been called in . But how did a certain — and very familiar — blue police box wind up buried in the ruins of Pompeii ? The TARDIS has landed , but with an odd fault : it won ’ t tell the Doctor where or when it has materialised . Upon exiting , the Doctor and Mel meet a slave , Tibernus , who takes them for emissaries of the goddess Isis . He tells them it is the twenty - third of August ; and the Doctor makes a sudden realisation : it is the year 79 AD , and they have landed in Pompeii — and it ’ s volcano day ! Or , almost . Mount Vesuvius will erupt tomorrow , in fact , at mid - day . The Doctor , preoccupied , lets Mel decide whether to leave or stay ; she opts to take a look around . In the city , her odd clothes attract the attention of the decurione Popidius Celsinus , of the city ’ s municipal court . He is intrigued by the rumour that they are messengers of Isis , as that goddess is his patron . Meanwhile , Tibernus reports to his owner , Eumachia , who is also displeased with the news . The travellers quickly make new — and not altogether good — acquaintances . The Doctor meets , and subsequently ( by exposing his cheating at dice ) offends , a disgraced gladiator named Murranus , who thereafter swears revenge on him . Mel meets another slave , a brothel slave named Aglae . Both are interrupted by an earthquake . Mel is disturbed to find that the locals dismiss the quakes as the displeasure of the gods ; they refuse to accept any actual danger . However , there ’ s a problem : the TARDIS is gone , buried beneath a building that collapsed in the quake . Unable to dig it out on their own , the Doctor and Mel are now trapped . The Doctor is strangely unsurprised ; finally he tells Mel that he expected this , as he knows that the TARDIS , in the year 1980 , will be dug from the ruins of Pompeii . He has encountered this before , in his fifth life , courtesy of UNIT ; and now the time has come . Mel refuses to accept defeat , and promises to solve their situation . She goes to seek help , while the Doctor returns to the inn — owned by a woman named Valeria — where he humiliated Murranus , who is now thankfully not present . Elsewhere , Eumachia meets with Celsinus , and tries to get him to help her expose the Doctor and Mel as impostors . She also buys some of Aglae ’ s time at the brothel , and questions her , then beats her . Mel interrupts and stops her , but Eumachia is not deterred . Later , Celsinus invites Mel to dinner ; she accepts , knowing that he has the means to get help in digging out the TARDIS . The Doctor joins her there , as does Eumachia . The dinner goes badly , and ends in an argument ; however , the Doctor has come to his senses now , and vows to do what he can to save himself and Mel , though he knows he is fighting time and paradox itself to do so . In the meantime , he tells Mel to leave the city so that she will survive if he runs out of time . However , Eumachia brings a squad of guards and has Mel arrested , on ( admittedly false ) charges of theft . During the night , the Doctor realises he has overlooked something both obvious and important . He drafts Aglae to help him rescue Mel . Meanwhile , Celsinus visits Mel in the local gaol . She admits that she lied about being a messenger of Isis , but denies the theft . After some debate , he decides that she is probably innocent , and that he was manipulated by Eumachia ; he determines to have her freed — and it should only take a few days … Mel , dismayed , sends him away . She barely has hours , let alone days . The Doctor meets him on the way out , however , and hypnotises him — along with the guard on duty — and frees Mel . Aglae will take her out of the city , and the Doctor will search for the TARDIS ; he realises that the building that collapsed was excavated much earlier than 1980 , meaning it is not the location where the TARDIS was found . The TARDIS , therefore , has been moved . Mel and Aglae try to leave the city , but are caught by a gate guard . Aglae knocks out the guard , and they hide in the nearby necropolis . They are caught again by the same guard when they try to leave in the morning , and locked up again . The Doctor returns to the inn , but Murranus — who is fortuitously drunk — is there . Murranus threatens Valeria into helping him capture the Doctor ; she does so , against her will , by drugging the Doctor ’ s drink . Celsinus meets with Mel again , and she tells him the whole truth . He doesn ’ t want to believe it ; but he tells her that Eumachia has described the TARDIS , and when she confirms its detailed description , he believes her . He releases Mel and Aglae , just as another tremor strikes . Vesuvius is about to erupt . The Doctor awakens in the local amphitheatre , where Murranus waits . He is forced to fight . At first he refuses , but Valeria comes to his defence , and he is forced to fight back to save her . He is about to be killed … when the mountain erupts . In the ash and darkness , the Doctor and Valeria escape ; Valeria believes he must be a messenger from the gods after all , if he has power to make the mountain explode . He brushes that aside , and sends her away , warning her to flee the city . Mel leaves Aglae with Celsinus , and makes her way to Eumachia ’ s house . Eumachia admits to taking the TARDIS , but refuses to reveal its location ; she insists that the ongoing destruction is because of Mel . Tibernus reveals that the TARDIS is in the necropolis , but he does not know which tomb ; he only has an approximate location . He refuses to flee , choosing to stay with his mistress even in the face of death . He and the other slaves will die , as will Murranus and the other gladiators , who have retreated to their barracks . The Doctor meets up with Celsinus and Aglae , and passes Valeria to them , warning them all to flee . They do so , but lose Valeria in the crowd ; history will record that she died in Pompeii . They escape the city , but their fate is unknown . Meanwhile , the Doctor finds Mel , and they make their way to the necropolis … and as the city chokes on ash and smoke , they locate the TARDIS , just in time . The TARDIS materialises in 1980 , just before the earthquake that unearths it . Mel comments on the fate of their friends , and the Doctor reflects that they may have survived ; he does not know , but chooses to believe they survived until he sees proof to the contrary . She asks why they spent three days waiting in the TARDIS before leaving . The Doctor says that it is so that the ash and lava would harden around the TARDIS , forming a TARDIS - shaped cavity , into which he then materialised it in 1980 . Thus the timeline is preserved , and no paradox results . They exit the TARDIS and hide just in time to see Captain Frost approaching the scene of the discovery ; in a few days , they will go to UNIT and reclaim the TARDIS , and be on their way .