Let's get the obvious stuff out of the way. This was an excellent anniversary story that delivered everything that could reasonably have been asked of it, and much more that couldn't even have been imagined. There's so much to talk about, and I'm going to forget some things, but here's what still stands out for me now, a month later.
It begins with a very original opening or, rather, the original opening. Monochrome titles and Delia Derbyshire's unmatchable version of the theme - both still gobsmackingly good and, after a sensible rest from our screens, still retaining the power to shock and delight. Better yet, is there a more suitable way to drive home the point that this is still the same show. Like Trigger's shovel, everything has changed, but this is still Doctor Who.
Much of this episode is whizz-bang fantastic, with great stunts and some extraordinary 3D action over Gallifrey. There are plenty of these kisses to the past throughout the show, but most of them are almost invisible jokes, tucked away in props or muttered comments, to be enjoyed on repeated viewings. But, although the bells and whistles are marvellous, although the Daleks, Zygons, UNIT and Rose all return for their anniversary bow, they're not essential to the unwinding of this story. At last the focus of the programme has come to rest squarely on its lead character, and the result is spellbinding.
The essence of drama since ancient times has been someone talking to themself. Only Doctor Who, of course, can take a soliloquy and turn it into a three-handed conversation. But the point is that this is not a multi-Doctor story in the way we have known it before. In the original series, the character of the Doctor was so much less well defined and, if different versions met, it was their costumes that varied most, and any differences of demeanour resulted as much from the personalities of the actors as anything else. In The Five Doctors, they take turns being the Doctor, even when they're in the same scene. This time we get something else.
That scene in the dungeon of the Tower is centrepiece of a wonderful drama, the lynchpin of the story. Three versions of the same man, locked together, forced to converse and through doing so revealing how they have changed. These aren't personality clashes forced by the arbitrary neural-rewiring of regeneration - at last, the Doctor is portrayed as someone affected by the passage of time, a character moulded by events. Imagine yourself, at 20, at 35, at 50 - trapped in a room. The youngest is eager to find out what happens; the oldest, perhaps, has tried to move on. In between them is a man who regrets his mistakes, who resents the vanished opportunities of youth, and who can't forgive the old man for the fact that he seemingly no longer cares.
That's what we get here, told through three superb performances. Hurt, the young Doctor, watches his older selves with some humour. Smith, impossibly old, trying to remember, but it was all so long ago. Tennant does it with a look. When the Eleventh Doctor mutters that he has no idea how many children were on Gallifrey, the Tenth glances at him - surprised, disgusted, but most of all horrified. What will I become? For most of us, that's a disturbing thought - how much more so for a Time Lord.
Moffat (such a clever trick with the sonic - we thought they were different, but they were always the same) forces even the most casual and incurious member of the Saturday night audience to see these three actors as the same man, not just sharing a title, but the same internal life, the same memories and thoughts. The younger can rekindle hope in the older two; the old dogs can show the whelp that the future is worth fighting for. Youth and experience combine to undo past mistakes, without evading their consequences.
The Doctor is the centre of the episode, of the story, of the whole anniversary, and the restoration of Gallifrey is a fitting present for the old man. It's very slickly done too, the technology of it so far off the scale that it doesn't, can't and shouldn't matter that we have no idea how it's being achieved. If you're worrying about that when the skies fill with TARDISes, I can't help you. Most importantly, perhaps, Moffat manages to reengineer the fate of Gallifrey without trampling over what has gone before - the Ninth Doctor will still be guilt-ridden and traumatised; in another room, Rassilon still plots his own escape. And how fitting that the Doctor should be able to take his greatest defeat and turn it into a victory: Gallifrey not destroyed but saved, his own self not damned but redeemed.
Then, not content with giving us every single previous Doctor, Moffat throws in a couple of future ones. I must confess, the sight of Capaldi's Eyes made me gasp aloud and I'm sure that, even were I to make it to the 100th anniversary, that would still be one of the most thrilling moments in the series' history. But the killer blow belongs to that genius loci of Doctor Who, Tom Baker, back in the programme for the first time in thirty years to play a mercurial future incarnation. It's an emotional moment (how wonderful to see him and Smith together), and a suitably timey-wimey way to salute both past and future.
There's so much more to talk about (incredible direction from Nick Hurran, astonishing production design) but not enough time to do it justice. But I can't not say how good it was to have David Tennant back as the Doctor. I know some feel that his and RTD's era was being sent up slightly, but this really isn't the case - it was more of a greatest hits package, condensed perhaps but without condescension. And Moffat's tenure got just as much needle, not least Hurt's complaints about Smith's flapping hands or the childlike "timey-wimey" (gifting Tennant the best joke of the script: "I've no idea where he gets it from"). He, Hurt and Smith combined beautifully, and the result was brilliantly funny, even joyous - perfectly pitched for an anniversary episode.
Piper and Coleman were also excellent, the former's return astutely executed by Moffat: any further return for Rose herself would have been difficult, if not downright irritating, and her appearance as the Moment/Bad Wolf was just right - simultaneously full of meaning, portent and nostalgia. Coleman had a more difficult job perhaps. Companions can get lost or over-looked in the most straightforward of episodes, but holding her own amongst all this hoopla was no mean feat. Clara's contribution is impossibly important, for it is she who, at the last gasp, forces the Doctor to fulfil his promise. In that moment Clara represents every companion, and justifies the very existence of the role in the show. It is a big deal.
But Clara does something else, right at the top of the episode, that although easily overlooked might be even more important. She ploughs her motorbike through the TARDIS doors. Now, they can keep pulling off this trick every week as far as I'm concerned, because it is superb. It's a perfectly executed entrance shot - a breathtaking composition that takes Clara (and us) from an exterior location, through the TARDIS doors and into the studio set. But this is more than just showing off - this journey, replayed again and again throughout the show's history, is a strand of the programme's DNA, as distinct and as important as the Police Box, the music or the Daleks.
The very first episode, fifty years ago, pivoted around that extraordinary transition, dramatically, technically and in other ways besides. Perhaps we take it for granted, but every time someone moves through those doors, stepping from junkyard to shining white control room, or out into a petrified jungle, a space station, or a country house, we are witnessing the essential magic of Doctor Who. From the outside, that little box is perfectly unassuming - but once the threshold has been crossed, suddenly the spaces on both sides of the doors are full of wonders.
