Twice Upon a Time (Doctor Who) and Time". This makes him the third actor to play the role in the television programme, after William Hartnell and Richard Hurndall (in 1983's "The Five Doctors") since the premiere of "Doctor Who" in 1963. Bradley previously played Solomon in the 2012 episode "Dinosaurs on a Spaceship". The first trailer for the episode was shown during the 2017 San Diego Comic-Con, revealing the return of Polly, a companion from the end of William Hartnell's tenure as the First Doctor, portrayed by Lily Travers, and Pearl Mackie as Bill Potts. Also confirmed were appearances by Toby Whithouse, writer of seven episodes
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