Aired 25 December 2015

Following a truly spectacular run of twelve episodes that often veered into quite dark and sombre territory, Doctor Who returns for its annual festive outing in a much more lighthearted- though nontheless incredibly enjoyable- outing. Clara is firmly in the past, and the Doctor has no memory of her other than her name, returning the focus more squarely to the Doctor as no new companion is on the horizon as of yet.

As the title blatantly states, though, River Song is unabashedly back and Alex Kingston perfectly recaptures her iconic role here. The central premise that River does not recognize the Doctor goes on for an astoundingly long time thanks to some necessary deception and evasion on the part of the Doctor, but it never wears too thin or feels unwelcome. In fact, that resulting banter between Kingston and Capaldi instantly prove what a dynamic duo they are while giving Capaldi yet another chance to demonstrate how adept he is at comedy. The scene where the Doctor pretends to be taken aback by the larger interior of the TARDIS is fifty-plus years in the making, and that alone is worth watching the entire episode. It’s a relief to see the Doctor get to have a bit of fun after the harrowing events he had been through over the course of the series, even as he just lays in the snow and laughs.

However, as River slowly realizes just who the man standing next to her truly is, both characters effortlessly switch to a more mellow dramatic state that so perfectly underlines what they truly mean to each other. Their final date on The Singing Towers of Derillium punctuates their relationship, even as the realization that River’s final fate first seen in ‘Forest of the Dead’ is looming. This may not be the quintessential River Song appearance that reveals a lot of information about the Doctor or her, but it’s still an immensely gratifying episode that further cements her place in the Doctor’s hearts and in the programme’s legacy.

The guest cast is quite good, though neither Greg Davies nor Matt Lucas is given too much to do with their roles. Davies does manage to fare a bit better playing (the head of) King Hydroflax, but this is very much a story with its focus on the Doctor and River. The large red robotic body that interchanges its heads and is so central to the story is grand in design but, again, it seems like there was further opportunity for it to flex its muscles as well. Also interspersed through the episode are some set action sequences that, though serviceable and visually strong, seem a bit disjointed from the story as a whole, never amounting to too much in terms of progressing the story. As always, though, the production values are top-notch and the entire episode is a visual treat from beginning to end.

The interplay between Capaldi and Kingston is so strong that the entire episode could have easily been built around that and their sometimes-ludicrous and sometimes-meaningful situations and tone together. If this truly ends up being the end of River Song on screen, it’s a fantastic farewell for her, exemplifying everything that made her character so memorable through so many of the Doctor’s lives. Only time will tell, and in the meantime Capaldi is set to continue his adventures through space and time.