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) Muggsy Smith became Mickey Smith. Davies had trouble coming up with how Mickey was supposed to be captured by the Nestene while waiting for Rose in the car, and finally realised he could be lured by a plastic wheelie bin. He commented that such instances of the ordinary being made scary made "Doctor Who" unique. Davies had to take out "oblique" references to the Autons being like terrorists, as the Eye was once a target of a terrorist attack. The entrance of the Doctor was something much debated; Tranter and other members of the production team wanted it to be