Did you catch Doctor Whos Joy to the World sly reference to a fan-favorite character?

Former showrunner/executive producer/screenwriter Steven Moffat returned to Doctor Who to present audiences with another magical and emotional Christmas special, "Joy to the World." While the Moffat-penned adventure focuses on a Time Hotel, a lonely but lovely woman (Bridgerton's Nicola Coughlan), and a mysterious briefcase, giddy Whovians have spied all kinds of Easter eggs along the way.

Some tie to James Bond, others to classic British TV, and still others to deep-cut Whoniverse lore.