An effective holiday farce that serves as a fitting end to the story of River Song. It’s not much more than that, but it makes no claim to be, and you can hardly fault a Christmas special for its froth. So, all told, good episode.
What really jumps out, though, is an idle comment Moffat made about writing it with the knowledge that it could be his last Doctor Who. He walked it back in a later interview, saying that he thinks that every Christmas, but it’s hard not to notice the lack of any forward-looking elements in the last few stories. This is the first time in ages a season has ended with essentially no lingering plot threads. Clara is sorted and departed, Gallifrey is found, the Hybrid is presumably dealt with. And with The Husbands of River Song we get a story that seeks active closure on River’s story, in a way not even Name of the Doctor did. It’s not that there’s no possibility of further stories, although at this point they’d have to take place post-Silence in the Library. And we still don’t actually know the circumstances under which the Doctor could tell River his name. But we’ve seen them live happily ever after, an explicit accepting of endings.
Obviously the reality is that Moffat’s not going. And I’m certainly not unhappy about that, although I wouldn’t have been unhappy had he gone either (unlike last year). But there’s a mindfulness to the possibility of this being an ending - a clear sense that Moffat made sure he’d be happy with this as an ending, as opposed to just knowing it theoretically might be.
So unsurprisingly, if he’s going to maybe go out on Christmas, Moffat does farce. Which is his most elemental state as a writer. His puzzle boxes and mysteries have always, in key ways, been farces with the jokes taken out, or, as in Let’s Kill Hitler, with the jokes left in. And he’s very good at it - probably the single greatest practitioner of it over the last quarter-century of television. All of this is on ready display here, with a wealth of well-executed comedic set pieces about River not realizing who the Doctor is. The “bigger on the inside” sequence is probably the funniest single one, although I think my favorite bit of farce is the “oshit the worship the guy who’s head we have in a bag” moment.
But the result is an episode that’s a bit lopsided; much as I loved that bit, almost everything after they land on the spaceship left me impatient for River to figure it out already. It wasn’t quite to the point of being bored - that’s more a Sleep No More or Before the Flood sort of problem - but it was definitely more than the Doctor and River doing a “she doesn’t know who he is” farce while being chased by a generic robot can strictly speaking sustain.
And then of course there’s the end, which is wonderful and perfect. The detail that gets me, unsurprisingly, is the Doctor consciously hoosing to finally take her to the singing towers. It’s a very Twelfth Doctor thing to do, but also something that feels like it comes out of the season we’ve just watched, which otherwise isn’t really something that happens here. And on the other hand, I quite like the idea that the Doctor will have, at a minimum, spent twenty-four years living with River on Darillium when next we see him.
What holds it together, though, is that Capaldi and Kingston are just good together. Capaldi has not been entirely well-served by the efforts to give him outright comedy episodes thus far (which is different from saying he’s not been well-served by the comedy bits), but this works for him. The trick, I think, is that it’s really played as an episode of River Song, with Alex Kingston serving as the main hero (which is nice, as despite that always having been the premise of River she’s never actually gotten to do it) and Capaldi misbehaving in the margins. It’s reliably funny and charming, and its quality is a lot of why the episode gets away with overstretching its plot so much.
But by and large, a simple little story that exists as the dessert course after the epic crescendo of Series 9, and a good way to end it that could have worked to end much more. Roll on Sherlock.