Theory:Doctor Who television discontinuity and plot holes/The Fires of Pompeii


 * The Doctor does not seem to recall, or at least does not mention, the events of The Stone Rose.
 * It is possible that the writers paid no attention to those events.
 * Generally, novels and other tie-ins are not considered canonical within a show unless specifically referenced in the show itself.
 * There was no need for him to mention it.


 * Donna says that the Doctor saved her in 2008 when Partners in Crime was set in 2009 and The Runaway Bride was set in 2007.
 * However, Christmas 2007 is almost 2008. She could simply have rounded up.
 * Additionally the Doctor may have told her the events of Voyage of the Damned was not a hoax and could be referring to that instead. She did after all say "you saved us all" and not just her.
 * Wilf could have told her about the events of Voyage of the Damned, then when he talked about aliens and teleporting, she could have asked about the Doctor, who Wilf could have described to her, then her knowing he saved them.


 * After the Doctor and Donna go into the TARDIS, their hair is full of dust and Donna is crying but when they go back, they are both immaculate.
 * The TARDIS is a time machine, they could have gone so far in the TARDIS and then when the Doctor was finally persuaded they had already cleaned themselves up.


 * The chameleon circuit, although broken, allows the TARDIS to remain hidden to the untrained eye so how did Caecilius spot it to offer to buy it?
 * The TARDIS uses a perception filter. It is visible but you don't want to see it. Caecilius wanted to see the modern art, so the perception filter didn't work. As for the others, once attention is drawn to it, it can easily be seen. Humans tend to overlook the TARDIS, which is a feature of the chameleon circuit.


 * How can Caecilius move the TARDIS into his house so fast, especially when there was an earthquake?
 * Previous episodes have shown that several stout men can pick up and move the TARDIS.


 * When the Doctor returns to Caecilius' house to save him and his family, why is the inside of the TARDIS so bright?
 * For dramatic reasons. Also, from Caecilius' point of view, this magnificent temple of light is his and his family's salvation. This is also consistent with previous depictions of a great light sometimes shining from within the TARDIS.


 * How could the Pyrovile possibly have fit in the escape pod?
 * There is no evidence that the Pyroviles were the same size when the first arrived, and/or so many of them.


 * Why can't the soothsayers see the Doctor's name? They seem to be able to see everything but.
 * The Doctor has shielded his memories. Cassandra said as much whilst invading his mind in New Earth. The Carrionite Lilith had similar difficulty in The Shakespeare Code.


 * When the Doctor and Lucius Dextrus are having a battle of wit, Lucius says something like "every sun must rise", to which the Doctor replies "but the son of a father must also rise". Lucius says the Doctor is witty, but he is meant to hear the Doctor speak in Latin, meaning he wouldn't hear "sun" and "son" as the same word. He wouldn't understand the pun, and surely wonder why the Doctor was suddenly talking about something else.
 * The TARDIS's translation mechanism is far more advanced than any human attempt at automated translation, and its translations may be liberal enough to communicate punning intent and quality across languages. Even without the pun, the comparison of a son rising as does the sun could be understood as meaningful metaphor.


 * The purple robes given to Donna are likely an anachronism, as purple dye at the time was far too expensive for a mere marble merchant to afford. See Tyrian Purple.
 * Caecilius is rich enough to spend money on 'modern art' in an attempt to appear to have status, it would make sense he would buy rich-appearing clothing in another attempt at the same thing.


 * The Doctor calls Donna's clothing a toga. It is a stola, a dress worn by Roman women. Togas were exclusively men's clothing in 79 A.D., and a woman who wore a toga would be a prostitute, or accused of adultery.
 * The Doctor said it as a joke, and most Roman draped clothing is commonly referred to as "togas" by modern non-specialists.


 * The Doctor was able to save the family from a fixed point in time where they should have died. He said that some things in time are fixed and cannot be changed, yet he saved the family.
 * Perhaps the eruption and the deaths of most of Pompeii were the fixed points in time, but the family was not part of that fixed point.


 * Why is Lucius' arm solid stone when the High Priestess can move freely?
 * They are at different stages of their respective transformations.


 * The prophets were presumably unable to foretell the eruption because it would not have happened if the Doctor had not altered the timeline. However, if the future sight of the prophets was caused retroactively by a rift in time due to the explosion itself, if the eruption had not occurred, they should not have been able to see into the future in the first place!
 * We don't entirely know how time works. As the Doctor said, it's a "ball of wibbly-wobbly timey-wimey stuff".
 * We know what the word "fixed" means. This sort of thing is often a problem for Dr. Who continuity, if something is "fixed" (non-moving) it can't be "wibbly, wobbly (which implies movement).
 * In this episode the Doctor both describes the Vesuvius eruption and its consequences as a fixed point but at the same time describes the Pyrovile involment history as an "alternative". Which it also is because Davros' theft of Pyrovilia is not a fixed point. So what, were the Pyroviles in danger of breaking a fixed point and the Doctor conveniently showed up and stopped them? Well that's lucky for time.
 * Perhaps everything the Doctor said about "fixed points" was just a way to get across the idea that he's not allowed to change it? After all, in The Waters of Mars he changes what he refers to as a "fixed point". So perhaps what he means when he says "fixed" is "this can't be changed without massively altering the course of history". Although, tbf, it seems that the real "fixed point" of that episode was Adelaide's death, since she still dies and still spurs her granddaughter to journey through the stars.
 * Actually, the doctor did think they were in Rome. That points to it probably being the tardis intervening as it has been proven to do - "I may not take you were you want to go, but I ALWAYS take you were you need to go"!.


 * Donna doesn't speak the Latin correctly, but instead use an Anglicised version of Latin. For example, when Donna says "veni, vidi, vici" the correct Latin pronunciation should be "weni, widi, wiki". It is understandable that the man would hear Celtic instead of Latin and therefore this shouldn't represent the TARDIS translation circuit.
 * Correct pronunciation of Latin is debatable, as evidenced by the difference between the so-called "Church" and "Classical" variants. The particular intonations used over 2,000 years ago by a city which was wiped out are very hard to accurately judge.
 * Also, that would not sound like Celtic. When Chekov on Star Trek mixes up his Vs and Ws, it sounds like English with a bizarre pseudo-Russian accent, not like some arbitrary different language only distantly related to English. At best, it would sound like a British or Gaulish dialect of Latin (and even that's unlikely). The only explanation is that the TARDIS translates their Latin to Celtic because that's for some reason its best guess as to how to represent them speaking a foreign language in the middle of their English.


 * Lucius Petrus Dextrus is said to mean 'Shining Rocky Right-hand' in Latin, but in Latin 'Shining Rocky Right-hand' translates to Rutilus Petrosus Dextram.
 * The name is described as "roughly translating." While the translation is by no means exact, the name is derived from similar roots as the "correct" translation, close enough to be evident that it was intentional.


 * Given the reason Pyrovilia vanished, why did the Doctor's fixed-point-in-time sense desert him in Genesis of the Daleks?
 * The Time Lords were still around and actively maintaining the Web of Time in Genesis of the Daleks. They presumably could have re-stitched the metastructure of history around the absence of the Daleks. Especially since the Time Lords sent him on the mission in the first place, after having worked out the possible futures and the best way to change history.


 * Would the Doctor really leave Donna at the eruption, or was the TARDIS about to leave an empty threat?
 * The noise did seem to go on for longer than usual, so The Doctor was probably using it as a warning to Donna for her to hurry up as she did seem more rushed looking as soon as she heard it, possibly to make her think he would leave her.


 * Why did the Pyroviles come up with a massively convoluted plan to get the humans in Pompeii to build them the circuit, instead of just coming out of the ground and politely asking them to help them out?