10 Ways Doctor Who Was Almost Completely Different
4. David Tennant Almost Stayed For Series 5...
Before Matt Smith was cast as the Doctor for Series 5, Steven Moffat came very close to doing things much differently. In fact, David Tennant almost stayed in the role for one more series, as opposed to bowing out in The End Of Time.
Moffat was announced to be taking over for the fifth series in May 2008, but it wasn't until October 2008 when we learned that Tennant would be leaving. In the time between those May and October announcements, Moffat held discussions with Tennant, and ran him through what Series 5 would look like if he chose to carry on playing the Doctor.
In Tennant's Series 5, the Doctor would crash into young Amelia Pond's garden (just like Matt Smith did in The Eleventh Hour) about to regenerate. Here, Amy would help him back into the TARDIS, and watch him fly off. She would then meet the Doctor again when she grew up, only to find out that he had no memory of their initial meeting in her garden.
As the series unfolded, we'd learn that the reason the Doctor can't remember meeting young Amy is because.. he hadn't yet. It was his future self that crashed into her garden, and the series would eventually make its way back to that initial scene, where the Doctor would then regenerate inside the TARDIS.
Elements of this outline were used in the Series 5 we did get, but when Tennant passed, Moffat had to rework things significantly. That wasn't the only problem the showrunner had to contest with at this time, either...