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 with his emotional attachment to the character; with little choice, he reluctantly accepts the situation. He breaks into tears as he informs his wife Heather (Lesley Manville) of the news, admitting that he doesn't want to leave the role. Before his final scene, Hartnell shares a brief exchange with his successor, Patrick Troughton (Reece Shearsmith). As the cameras are about to record, Hartnell looks across the main console and sees Matt Smith, who will play the same role nearly 50 years later. Smith silently acknowledges Hartnell's legacy before disappearing as Hartnell begins the scene. For the thirtieth anniversary of "Doctor