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
Doomsday (Doctor Who) trapped in the Void, so the Doctor sends them all to the parallel universe. Rose decides she would rather be with the Doctor than her family and jumps back to help him. The Cybermen attempt to stop the Doctor but are repelled by a converted Ms. Hartman, who has resisted the effects of her conversion and at least partially retains her sense of self. The Doctor and Rose open the breach and hang on to magnetic clamps as the Cybermen and Daleks are pulled in. The Cult of Skaro use an emergency temporal shift to escape. Rose's lever slips, and