The title for this year's Doctor Who Christmas special has been revealed as Twice Upon a Time.
Revealed at San Diego Comic Con, the Christmas special will mark the last appearance of Peter Capaldi as the Doctor, before he hands over the role to incoming Thirteenth Doctor Jodie Whittaker. Capaldi will be starring alongside David Bradley in the special, who will be reprising his role as William Hartnell's first incarnation of the Time Lord.
As for the title's meaning, that's open to interpretation. As obvious conclusion is that it's referring to the story starring two Doctors. After all, the episode title The Two Doctors has already been taken by the 1985 serial starring Colin Baker and Patrick Troughton. The riff on the old phrase 'once upon a time' could also be a nod to showrunner Steven Moffat's philosophy that Doctor Who, at its heart, is a fairy tale.
But of course, it's probably a reference to something completely unexpected and clever. We'll just have to wait to find out.
It has also been announced that Doctor Who companion Pearl Mackie is returning to the BBC sci-fi series after apparently leaving for good in the series 10 finale, with her character Bill Potts set to star in Twice Upon a Time.
The move will presumably see her meet David Bradley’s take on the First Doctor as he joins forces with his later self, with rumour abounding that other former companions including Jenna Coleman’s Clara Oswald may also be saying their farewells to Capaldi’s Time Lord in the festive special.
Doctor Who returns to BBC1 this Christmas