Coughlan brings her own radiance to Joy, her beautiful round face and bright blue eyes shimmering with tears, her hair a halo of gold, framed by a bright red beret and matching jacket. Visually and emotionally, she is a shining symbol of the season, its warmth, yearning, and heartache. And in the end, she is the star this episode demanded.

Joy to the World was Steven Moffat's meditation on loneliness, showing how the Doctor and every character are worse for it.

The Doctor checks in to a very unusual hotel – here's how to watch "Doctor Who" Christmas special "Joy to the World" online on BBC iPlayer in the UK and on Disney Plus in the US.