The episode introduces Joy, starring Nicola Coughlan (Bridgerton, Derry Girls), who checks into a London hotel in 2024, only to discover that her quiet stay is anything but ordinary. When Joy opens a secret doorway to the Time Hotel, she discovers danger, dinosaurs and the Doctor. But a deadly plan is unfolding across the Earth, just in time for Christmas.

Where has the Doctor been? What is going on in Joy’s hotel room? An old enemy of the Doctor’s is lurking in the wings and all of human history hangs in the balance. Can the Doctor save Christmas, everywhere, all at once?

https://www.themoviedb.org/tv/239770-doctor-who