Speaking to CultBox on the set of ‘The Day of the Doctor’ in Cardiff earlier this year, the writer commented: “I knew the story we wanted tell and certain things in the kit of parts that we could tell it with. That has to be the priority, otherwise you might as well just have a walk-down, a curtain call…”

Hinting at the returning of more past characters in the special, he teased: “It can’t all be curtain call. Not that I’m saying we don’t have a curtain call!”

Moffat added: “It was a very, very, very difficult script to start writing, because it had to be epically ambitious. I’ve never written anything quite like it. It was the most terrifying thing I’ve ever done.”

The writer explained: “I knew what I wanted to accomplish. I think there’s a tremendous danger if you attach the word 50 to anything that you are arranging a state funeral and a retrospective. I wanted it to be the show that ensures the next 50 years – it does celebrate the last 50 years, trust me, people seem to worry that I‘m not going to do that. It celebrates the legend, rather than saying ‘it’s really old, you know’.”

He joked: “You don’t want to say that to kids, do you? ‘This is something your grandparents watched!’ You want it to be an absolute forward thrust.”

‘The Day of the Doctor’ will air at 7.50pm on Saturday 23 November on BBC One.

> Find out all the latest info on ‘The Day of the Doctor’ in our news summary.

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