Of all the episodes of Doctor Who ever to air, none have quite the same weight as "The Day of the Doctor", better known as the show's 50th anniversary special. As head writer, it fell on Steven Moffat to pen the episode which, as you can imagine, was a monumental task given everything it had to achieve, for fans and the franchise alike.
In an article for RadioTimes, Moffat describes the burden of crafting the most important episode in the history of the series:
I don't think I've ever worked on anything that was as difficult, terrifying and as much of a responsibility as writing the 50th anniversary episode of Doctor Who. I wanted everybody to love it. I knew that was impossible, but I wanted people -- from those who had never seen it, to the absolute diehard fans who hate every episode I've written -- to love it. So it was monstrously stressful and very hard: the uncastable cast, the impossible brief, the unwritable script...
I can remember sitting with my wife saying, "I can't tell if it's good any more, it could be rubbish -- I'll have to leave the country. I'll have to fake my own death."
Covering more recent events, Moffat goes on to talk about the passing of the TARDIS-shaped torch from Matt Smith to Peter Capaldi and how the actor tends to shape The Doctor, rather than the other way around.