As much as I enjoyed this episode, it misses a major trick by underselling its key dramatic moment far too cheaply. The result is a good but slightly puzzling story, when perhaps we could have had a transcendent, wonderful one.
I'm not moaning about the beneficence of the Time Lords, or the eventual regeneration - no, the critical moment turns up about half-way through and it passes without any fanfare, despite the fact that it is possibly the most extraordinary thing to happen in Doctor Who since he first regenerated, possibly since he abandoned Susan.
The Doctor stops.
For as long as we have known him, the Doctor has been running. Running from the Time Lords, running around the Universe, running from his responsibilities. When the Time Lords caught him, they punished him by fixing him in place, pinning him to Earth, and it infuriated him. The thought of resuming his presidency made the Fifth Doctor wince. The Tenth Doctor ran from his own demise and then railed and fumed when it finally knocked.
Then here, on Trenzalore, in his last life (more on that later), he finds himself in an unwinnable situation. A stalemate that cannot be broken, only preserved. A peace that can only be enforced if he gives up his travels, his lifestyle, his freedom - and stays still for the rest of this life.
It's a big moment, no? And although I'm not sure I'd want the wailing and gnashing of teeth we saw from Tennant in The End of Time, I do think it could have, and should have, sat a little more heavily on the Eleventh Doctor. As it happens on screen, it's not even clear that he has actively made such a decision. It might be that he just reacts impulsively, and that he only stays because the TARDIS doesn't promptly return from dropping off Clara.
Either way, I think the story suffers from not clearly showing us the Doctor's resolve at that moment: to stay no matter what. We need to see that he knows what he is giving up, even if it is done willingly. Without it, especially on a first viewing, the episode seems to drifts into unfamiliar territory after that point, with voice-overs filling in great swathes of lost time, and the youthful Eleventh Doctor disappearing from the story. Eventually, once Clara comes back, we get a scene where some of this is explained - but it would have been better to have known where we were going, rather than be told where we had arrived.
The same is true of the revelation (during that same conversation) that the Doctor is in his final body. I remember that when The Curse of Fatal Death aired some silly fans complained that this it was part of a BBC conspiracy to finally kill off Doctor Who by using up all his future regenerations in one go. I never had any truck with the more paranoid elements of fandom, but it is head-spinning to have whizzed from a tally of ten regenerations to twelve, and now thirteen, all within six months. There is no sense in which Doctor Who is an exhaustible resource, but I do think that I was rather looking forward to having a Thirteenth Doctor that threatened to be the last. It would have been interesting and new to see him affected by a sense of his own mortality, and it would have leant some extra drama to events building up to his eventual (and inevitable) regeneration.
But here again, we don't get to savour the moment. Thanks to the War Doctor and Tennant2, it turns out that we have already had our twelfth regeneration and that the Eleventh Doctor has been mortal all this time. I wish we had known (it would certainly have added weight to The Impossible Astronaut, if nothing else) but instead we have only twenty minutes or so to adjust to the idea before the whole matter is resolved.
I sympathise with the fannish fear that the notion of a 'last' Doctor is a precarious one - dangerous rapids that should be navigated as quickly as possible - but Moffat knows the show has never been more secure than it is now. The hurried culmination of the regeneration cycle has come about more as an accident of scheduling and casting as anything else: the co-incidence of the Fiftieth barrelling straight into a Christmas Special on the one hand, and the unwillingness of Eccleston to return for the anniversary coupled with Smith's decision to leave on the other.
Anyway, once again I have spent a great deal of time describing a small quibble. I have others that can be dealt with more quickly: I don't like using monsters piecemeal like this - it's useful shorthand, but their threat and their significance is reduced as a result. The long-promised answers we got weren't so much loose threads tied up as dead-ends closed off in so much that the answers didn't reveal but merely made the questions redundant. And although the latest explanations of The Crack and the Oldest Question make sense, they do have a whiff of reinvention about them.
But again, these are tiny quibbles and although it could have been even better, this was still a very enjoyable story and full of things to love. The opening ten minutes was completely manic, but chock full of some great jokes; Handles was a lovely addition and a K9 substitute with all of the advantages and none of the problems. Smith doesn't disappoint (has he ever?) and Coleman continues to shine as Clara, a companion who gets better and better as time goes on. Even if she was dangerously peripheral for some of this story, her intervention was crucial (as in The Day of the Doctor) and her reaction to the regeneration, when it came, was fantastic: for the first time in the new series (alright, unless you count Journey's End), the Doctor's demise was witnessed by someone who knew what was happening. Her fear and anxiety were thrillingly discomforting.
And the end itself was lovely: the bow tie discarded, tumbling to the floor; Amy's apparition, benevolent and cathartic... And then, in an instant, he was gone and a new man stood in his place. That was a great trick. It feels right to try and wrongfoot an audience that might think it knows the score. Capaldi doesn't have much opportunity to show his credentials (on first viewing I hankered for him to appear in the bell tower and finish the job that the old Doctor had left behind..), but then that's not the point.
The point is that shimmering blink of an eye when everything changes, when everything is up for grabs and for once, as the TARDIS careers off through the Universe, the question is not where next, but Who?
I can't wait to find out.