The Fires of Pompeii.

"Hello, and on The South Bank Show tonight we'll be discussing the Doctor Who episode The Fires of Pompeii and consider its wider implications within the mythology of the series."

TV One of the first jokes I ever read/heard/not sure about the new series was via a trailer which was shown in the weeks leading up to the broadcast of Rose which was filled with special effects and explosions and which fans were terribly excited about until they realised it was for a docu-drama called Supervolcano about a supervolcano. I was hoodwinked for the first few seconds but then more impressed by the proper trailer because Billie Piper was in it and she was (still is) nice. At that point though I didn't ever expect that Doctor Who would even be able to afford an exploding mountain episode set in Roman times, despite what Verity and co were ambitious enough to attempt in the 60s.

But here we are four years later, that mountain has indeed exploded and Russell and co have produced yet another really, really exciting episode. Taking full advantage of their time on the set of the defunct HBO series Rome, this was an episode that unlike Daleks in Manhattan had depth of field and actually managed to feel as though it was recreating a historical point in time, of a society in peril. This was aided by some great performances from the likes of Peter Capaldi and the always underrated Phil Davis (if only North Square had been a hit) and fantastic special effects from The Mill, stretching once again what you'd think was possible in television drama,this was the most convincing blast we've yet seen on screen. About the only disappointment was that this didn't turn out to be the pure historical I'd hoped for, but those magma monsters were really rather good, about how you'd hope the similar shapes from Shada would have looked given a larger budget and a lack of labour disputes.

Brilliantly, though, what might have got by on being a simple runaround with a bit black humour and old school threat in relation to whether the regulars will be able to find the TARDIS and disappear back into the vortex before hell rained on Pompeii, was given a far greater philosophical depth by the introduction of the franchise's perennial question about the extent to which the Doctor is allowed to change history. One of the first ever stories, The Aztecs, wrestled with this issue, albeit at a more sedate pace, and it's kept returning ever since, through the Charley Pollard arc in the Big Finish audios and reaching its more recent apogee in Father's Day in which we saw the grotesque results of history being deliberately changed.

My impression has always been that the Doctor can change only the history that he's aware of. In other words, since he knows the outcome of Hitler's rise to power he can't meet the young artist he was before and try and convince him to follow that career path instead of entering politics (for a version of what that might look like though, look no further than the John Cusack's failed attempt in the film Max). On the other hand he could quiet happily start a revolution against the Company in The Sunmakers because he didn't have a bloody clue what was happening on Pluto in our far future. Having already rationalised that for myself, as you can imagined it rendered that rather long political discussion in Lawrence Miles's Eighth Doctor novel Interference, in which the Doctor's harangued for choosing his revolutions a bit of a slog.

Thankfully, the episode didn't contradict what I thought; the Doctor did give that glorious speech about having an awareness of what's flexible and isn't in time but as we saw, his awareness of events is still mutable. He didn't know that he would, as in the nostalgically referenced The Romans (dvd release for that shortly then) and The Visitation, become part of the established events, or importantly the motivation behind them, inadvertent in those cases, premeditatedly (to an extent) here. It confirmed my other theory that for all the timey-wimey stuff we Ahistorians look to in order to rationalise multiple versions of Human Nature and how the audio The Fires of Vulcan can still be part of the Whoniverse, in terms of how historical events are played out, the timelords are already a part of history (in much the same way as The Master was already in London for Smith & Jones and Scaroth in Paris for City of Death). We're just watching/reading/hearing how that became so. Which is why perhaps he could allow Caecilius's family to survive; he was meant to, and Donna made him understand that. Plus, who else was going to live to invent the 'volcano' word?

To make this the thematic core of the episode, the emotional stick with which to smack Tennant and Tate over the head, and then throw it out on a Saturday night after John Barrowman's odd-ball new gameshow, was really, really brave. Within that too, to drop in all of that talk of soothsayers, nature of cults (that c-u-l-t-s) and the passing into of your offspring thereof was just so very impressive. True, the series has annexed this territory before in The Pirate Planet of all things and the implications of joining a sisterhood were discussed by Shakespeare in Measure for Measure, but then it was one of Douglas Adams' sideshow ideas, here it was at the very centre of the story and expecting the audience to think. Just as the series was getting a reputation for being an empty sparkly run-around (something I didn't countenance myself), once again it was producing a piece of apposite superior excitement.

Not even a pre-show, droning Ofcom telling off could bring down this bird. And hanging in its claws were Dave and Catherine (Cathy?), the former offering his usual note perfect performance and the latter demonstrating that you know, you people who thought that casting in her in the series and bringing back the runaway bride was a mistake, you're all fools, the lot of you. These characters are great double act, equals in so many ways, Donna doing everything a companion should do and just a little bit more. (Many great lines: "You just defended us using a water pistol? I bloody love you!" So say we all). Granted Rose defied those clockwork men, but largely through threatening them with the Doctor's wrath. Here it was Donna's own strength that was the menace and you have to imagine that even if the Doctor hadn't happened along, she still would have found a way to avoid the sharp end of the blade. That scene was hilarious.

But also in series drama you don't write and then hand a scene like the one in the TARDIS in which Donna pleads with the Doctor to save someone, anyone to an actress unless you're completely sure that she can carry it off. You protect them. At least you do these days. How often has a companion become derided simply because the actor didn't have the experience to deal with the material. Yet, here Tate was sobbing, giving the very human reaction we all would have to the horrific events that were unfolding looking at the one man who could change the outcome not doing anything. Tate proved that Andy, Russell and Julie all knew what they were doing in casting her, and simply you should have had more faith. You fools, again I say, you fools. Not naming any names.

A The Fires of Pompeii should be a fairly standard stand alone episode but like Tooth & Claw which introduced (god help us) Torchwood, through the words of the soothsayers, the potential arc threads of the fourth season were thrown wide open. What has Donna on her back? "She is coming back" is potentially a reference to Rose (although I wouldn't be surprised if there's a double meaning)? What is the Doctor's real name? Could it be The Other one? What is The Medusa Cascade? What's with all the rifts in space and time (another once cropped up here when Pompeii went bye-bye)? And just to make you really shudder have you noticed how the Doctor's suddenly mentioning the Shadow Proclamation again and how like planets are disappearing like the Nestenes both things we haven't come across since that very first episode.

Also, what if the image of record time held in Gallifreyan Matrix, clearly taking a break in some pocket universe somewhere, shows that the Cambridge family reference should have died and that in saving them the Doctor's stretching the web of time? Like the random dropping of the sonic-pen in the bin in the opening episode, all of these little changes to the timeline, when he lets his humanised nature get the better of him are finally going to catch up with him, as with the aforementioned Charley-arc, a range of subtle changes in the timeline, creating enough breaks for something horrific to break through. When that episode didn't end with the TARDIS back in the vortex, but six month's later as the family were making waves in their new adopted society, I thought like poor old Lucy in the audio Seasons of Fear, that horror would appear and eat them up. Instead, we were presented with something that could simply be a commemoration of the power that saved them, or a ripple which could have similarly grave implications as the seasons develops. See this post at The Doctor Who Forum for a range of other crackpot interesting theories, some more likely than others ("the Doctor walks with stardust in his wake... Astrid must be coming back and she's a TARDIS..." etc).

Next time on The South Bank Show: Ood no you don't.