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
Astrid Peth be the next companion after Martha Jones (played by Freema Agyeman) on 14 August 2007. Astrid's surname, Peth, was confirmed in the Christmas edition of "Radio Times". Davies has stated that the character was always going to be a "one-off" even before Minogue was cast and that Astrid would demonstrate "a whole new take – again – on what a companion can be". The name Astrid Peth generated some speculation before the episode's broadcast over the findings that "Astrid" is an anagram of "TARDIS", and that "Peth" means "thing" in Welsh. However, the episode established no such connection. On "Doctor