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 Doctor (Doctor Who) Within the fictional narrative, the Doctor is a Time Lord from the planet Gallifrey who travels through time and space in a dimensionally transcendental – "bigger on the inside" – time machine: the TARDIS (Time And Relative Dimension(s) In Space) which takes the exterior form of a 1963 police telephone call box, and retains the appearance throughout the programme. The Time Lords have dedicated themselves to overseeing all of time and space without interference. The Doctor chose to leave home by stealing an obsolete TARDIS model as revealed in the 1969 serial "The War Games" and depicted in the 2013