Doctor Who: 13 Cool Details Steven Moffat Just Revealed About The Girl In The Fireplace
12. The Episode Was Being Written Before Series 1 Aired
Getting a full season of Doctor Who on the air every single year is an enormous challenge, especially during the Davies and Moffat eras, when they had to make thirteen regular episodes - and one special - per run.
So many original ideas have to be thought up, so many crazy sets have to be built, so many costumes have to be created, and so many special effects shots have to be rendered. It's a very complicated show to make, and because it needs to be produced relatively quickly, there's often a bit of overlap between the production of separate seasons.
Case in point: Moffat was actually writing The Girl in the Fireplace before Christopher Eccleston's 2005 series had started airing.
Rose - Eccleston's first episode - aired in March 2005, while The Girl in the Fireplace was filmed in October 2005. This means that Moffat had a good six or seven months to write his script, which is quite a long time for a single story.