3. Timey-Wimey Regeneration Series 5 Episodes 1 & 13
BBCBecause of how far in advance plans were made for Series 5 (The Writers Tale has a text message about Steven Moffats decision to succeed Russell T. Davies that is dated September 2007), considerations had to be made about whether or not David Tennant would stay on for Series 5. To this end, Steven Moffat planned what he would do if Series 5 featured the Tenth Doctor. In an article for Doctor Who Magazine, Moffat revealed that he immediately assumed if David Tennant did stay then Series 5 would be his last, so developed a rough outline with both the beginning and end of the series centring around the Doctors Regeneration. In Episode 1 we would see a gravely injured Doctor who meets a young Amelia Pond but does not recognise her when he meets her later in her life. Episode 13 would have ended on the revelation that the Doctor seen in Episode 1 was from the finale and about to Regenerate. A case of both a wibbly-wobbly timey-wimey ball and the first face this face saw. However, as soon as David Tennant decided not to stay on, this framing device was no longer needed and Series 5 became a simpler more linear story, albeit still with an important time loop plot device in the finale. Now we'll just have to wait and see if Steven Moffat can resist reusing this for the Twelfth Doctor.