Doctor Who (series 4) Astrid Peth, who died during the events of the episode. The companions in the regular series had all been in the lead companion role previously: the primary role of Donna Noble, who was introduced in "The Runaway Bride", was played by Catherine Tate for all thirteen episodes. Her return was announced by the BBC on 3 July 2007. Freema Agyeman, who portrayed the Doctor's companion Martha Jones in series three, returned for "The Sontaran Stratagem", "The Poison Sky", "The Doctor's Daughter", "The Stolen Earth" and "Journey's End". Billie Piper, who played Rose Tyler from the first episode of the new
The Doctor (Doctor Who) the actors who played the character were deceased. Since the programme's revival, there have been three multi-Doctor stories, the "Children in Need" special "Time Crash", the 50th anniversary special, "The Day of the Doctor", and the 2017 Christmas special "Twice Upon A Time". Before that, the only references to past incarnations (from 1963 to 1996) have been in the aforementioned episode "School Reunion" (in which the Doctor acknowledges having regenerated "half a dozen times" since last seeing Sarah Jane) and in drawings that the Doctor (who has temporarily become human to hide from the Family Of Blood) makes based on