Astrid Peth Who Confidential", Minogue describes Astrid as a "dreamer" and that meeting with the Doctor rekindles Astrid's desire to explore. Later in his book "A Writer's Tale" Davies discussed with co-author Benjamin Cook how he had originally named the character "Peth" in a treatment but it bugged him, he later renamed her to "Astrid" giving the reason that it "...sounds more spacey, more like a futuristing Doctor's companion". Despite Davies stating that the companion in "Voyage of the Damned" was "always going to [be] a one-off...little knowing that it would be Kylie Minogue", he has since stated that he would cast
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