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 Runaway Bride (Doctor Who) the subsequent series of "Doctor Who". Henrik's, the department store Rose Tyler worked in, and an employee holding an advertising banner for it, are featured in the background of the scene where the Doctor uses the cashpoint. When the Doctor asks about Lance, he says, "He's not a bit overweight with a zip round his head, is he?" This is a reference to the Slitheen. In the series 4 episode "Turn Left", a world where the Doctor did not meet Donna Noble but still fought the Racnoss is shown. In that episode, it is shown that without Donna there to