The strength here is within the characters - Trev is funny, warm, and relatable, and Anita is wonderful. Her relationship with the Doctor across the year, and that section, is the highlight of the episode - seeing the Doctor take that time to pause, to look at how he has been left alone, and seeing how by staying still he makes these friendships is beautiful, and so well developed.

Its unfortunate, that while developed well, Joy feels forgotten as the companion. There are certainly moments that she is more rounded, and given depth, but mostly she is the weak link, despite a good performance from Nicola Coughlan.

The Time Hotel is a fantastic premise, and developed well, paving the way for plenty of stories in the future to revisit (Big Finish...?). The Star Seed definitely feels like the afterthought, there are ideas behind it, but they aren't developed well, and feel superfluous to the strength of the story.

But I keep returning to this, because it is just so much fun for Christmas, and the beautiful character work - Moffat mastered the character of this Doctor, and I keep coming back to this story to see where these strengths shine.