Twice Upon a Time (Doctor Who) The Doctor paraphrases philosopher Bertrand Russell when he advises his future self that "hate is always foolish and love is always wise". Peter Capaldi reprised his role as the Twelfth Doctor. On 30 January 2017, he confirmed that the tenth series would be his last, and that he was set to leave after the 2017 Christmas special. The episode also sees the introduction of Jodie Whittaker as the Thirteenth Doctor, whose casting was announced on 16 July 2017. David Bradley appears in the episode as the First Doctor, having previously portrayed William Hartnell in the docudrama "An Adventure in Space
An Adventure in Space and Time of 1960s Dalek props crossing the bridge, in a recreation of a famous scene from "The Dalek Invasion of Earth" (1964). Interior scenes replicating early "Doctor Who" production at Lime Grove Studios were also filmed, with replicas of early television equipment being used. A number of the cast have appeared in "Doctor Who" at one time or another, most notably original companions William Russell and Carole Ann Ford. David Bradley appeared in the Series 7 episode "Dinosaurs on a Spaceship", while Jessica Raine was in the Series 7 episode "Hide" and the "Call the Midwife" charity cross-over mini-episode; Jeff Rawle