‘I’m the last of the Time Lords.’ Essentially Part Two of Rose, this focuses more on the new Doctor, including his first scenes without Rose as he instead partners with Jabe to investigate sabotage on Platform One. This means Rose spends a lot of the episode fulfilling the more typical companion role of getting menaced by the monsters and locked up in mortal peril, but even this feels like part of her character’s story: initial culture shock and uncertainty about what she’s got herself into. If this were a George Lucas production, Rose was all about her ordinary world, the call to adventure, meeting the mentor and crossing the threshold, this is her facing tests, allies and enemies.

Billie Piper is great: the little worried look she gives the Doctor as he pumps away at the TARDIS console, showing off about his frankly magnificent time ship, sets the tone for her realisation that she’s basically stranded long after everyone she loves is dead with a man she barely knows. The heart of this is about her pushing to know more about the Doctor, and his stubborn refusal to give her an answer: ‘This is who I am, right here, right now, all right? All that counts is here and now, and this is me.’ Instead, as if he’s the seventh Doctor torturing Ace, he forces her to endure what he’s had to go through: watching the death of his own planet, realising he is the last of his kind, finally admitting the truth to her when she might actually have a chance of appreciating what it means.

The ’last of the Time Lords’ mantra has become a bit diluted through over-use, particularly when Gallifrey came back and then got destroyed all over again. But back in 2005 it did feel quite mythic: the only time, I think, when mystery has been successfully reintroduced to Doctor Who precisely because it doesn’t try to layer on yet more irrelevant detail to the character (“I’m actually the Timeless Other Grandfather from the Pythian Dark Age!”), but instead strips away all of the boring continuity that had been accumulating since 1969. The implicit promise is there can never be an Arc of Infinity on RTD’s watch. For new viewers, all you need to know is the Doctor is the last of the fallen; for old timers – everything you thought you knew may no longer even exist. Everyone starts from nearly the same page. That’s genius.

And all of this unfolds against the backdrop of the end of the world with loads of funny-looking aliens (remember when we were teased the Moxx for a year by RTD’s Doctor Who Magazine column?) and Lady Cassandra, still for my money the best RTD monster, a narcissist so wrapped up in her own self and appearance as the standard of perfection that she has become less human than all the ‘mongrels’ she despises. The Doctor’s pitiless inaction, ‘everything has its time and everything dies,’ as Cassandra is ripped apart ties in to his earlier judgement on the planet itself: ‘I’m not saving it. Time’s up.’

There are problems with The End of the World, the mystery bit is over and done in pretty much a scene with fairly obvious culprits, and the Doctor having to very slowly bypass three massive fans to press a button is not the first time this kind of naff solution crops in the RTD years. But, for me, this is the episode that convinced me the show was in the right hands. It’s not dour and preachy, even when its politics are pretty blatant (‘when I said the great and the good, what I mean is, the rich’); it’s The Happiness Patrol (the Have a Nice Day ticket seems like an explicit callback); it’s The Curse of Peladon’s delegates or The Dalek Master Plans Planetarians; it’s The Ark (I expect the last people living on the planet have just departed for Refusis 2 when this begins). I wasn’t sure it could happen, but this made me fall in love with Doctor Who all over again.

Next Time: The Unquiet Dead