Doctor Who: 20 Things You Didn't Know About The Day Of The Doctor
7. The War Doctor's Regeneration Was Added At The Last Minute
The episode concludes with the War Doctor effectively shedding the guilt of the Time War and giving himself a new lease of life - quite literally - by regenerating into a brand-new form.
It's a crucial moment in Doctor Who history that shows us the previously unseen birth of the Ninth Doctor, but amazingly, it wasn't always part of Moffat's script.
In fact, he only added Hurt's regeneration at the last minute, at the same time he was writing The Night of the Doctor.
While it was disappointing that we didn't get to see War fully turn into Nine, it's always good to see a regeneration scene, and with Murray Gold's fantastic score and director Nick Hurran's sweeping aerial camera move, this was a solid one.