After 13 years the annual Doctor Who Christmas special is pretty much a British television tradition. But every so often there’ll come one that stands out from the usual festive fluff, with this time of the year reserved for the current Doctor to bow out and pass the torch onto the next incarnation. Following in the footsteps of 2009’s The End of Time and 2013’s The Time of the Doctor, Twice Upon a Time serves as the swansong for Peter Capaldi’s twelfth Doctor and the debut of Jodie Whittaker in the role, with Steven Moffat also stepping down as showrunner before Chris Chibnall takes the reins. The episode also sees the return of the very first Doctor – now played by David Bradley on the back of his portrayal of William Hartnell in the excellent 50th anniversary biopic An Adventure in Space and Time.