So it’s goodbye David Tennant again, and over to you Ncuti Gatwa! Except, no! The big twist in this twistiest of episodes – one that may well be the best hour of Who ever – is that the three-episode reprise of Tennant’s Doctor is not quite the end for him at all.
What seemed to be simply a canny way for Russell T Davies to bring some goodwill back to the Whouniverse, using a Tennant as a drum-roll for Ncuti Gatwa’s new reign, was not merely that, not just cynicism: it was a chance to crowd please a crowd in need of a damn good pleasing.
