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
Rose (Doctor Who episode) subdue. Rose investigates the Doctor and meets Clive (Mark Benton), who has been tracking the Doctor's appearances throughout history. Clive tells Rose the Doctor is dangerous, and that if he's there, something bad is about to happen. While Rose is talking to Clive, her boyfriend Mickey Smith (Noel Clarke) is kidnapped by a wheelie bin and replaced with a plastic doppelgänger. The fake Mickey takes Rose to lunch and attempts to question her about the Doctor, but the Doctor shows up and beheads the doppelgänger. The Doctor takes Rose and the plastic head to the TARDIS and attempts to use