I think that the Doctor and Clara are sort of celebrating this freedom that they have, to roll through time and space wherever they want to go, and are having a high time. I think they’re having a brilliant time. They’re really, really excited about the idea of adventure and they keep pointing themselves in that direction, but of course, being as it’s Doctor Who, that’s a dangerous thing to do, not just in terms of the dangers that they will encounter but also, you can’t have a good time for too long. You have to pay for it somewhere down the line [laughs].

I think [the Doctor]’s moving. I think that the nice thing about what we’re doing, what I find interesting about it, is that the Doctor’s still sort of looking for himself. So he’s changed to some degree. I mean, he hasn’t changed, he’s still the same, he still has the same concerns and worries and darkness if you like, but he’s embracing the present. But that’s really because he has a profound knowledge of the past and the future. In this incarnation he is, I think, sometimes prone to… He’s wiser than he often says. He knows that things can often end in great distress, but rather than focusing on that, I think he’s decided to have a good time. But it doesn’t mean that he’s not aware that darkness will fall… or whatever phrase I can think of that they can print that sounds good!

On how Clara’s teaching job fits in to series nine:

She’s still there teaching. She can be full-time teaching, because I can just whoosh her away and bring her back before she left. […] I love having the school and the fact that it’s Coal Hill School and also that the younger audience can related to that in a very clear way. She’s still very busy there.

On working with Game Of Thrones’ Maisie Williams in series nine: