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
The Chase (Doctor Who) the last appearance of Russell and Hill as companions Ian and Barbara and the introduction of Peter Purves as new companion Steven Taylor. In the TARDIS, the Doctor, Ian, Barbara, and Vicki are huddling around the Time-Space Visualiser, a television-like souvenir from their recent adventure at the Space Museum, which can pick up on any past event in the whole of time and space. The TARDIS then lands, and the Doctor confirms conditions are hospitable. Ian and Vicki leave to explore the desert wilderness. They find an ancient trap door in the sand. Inside, they are trapped — and become