Alex Kingston plays Doctor Who‘s companion from the future, brought back into his life to help him battle the dreaded Weeping Angels on Saturday, April 24 on BBC One…

What’s your take on the character – she’s quite enigmatic…
“Going back to when River Song was introduced two years ago, she’s a time-travelling archaeologist. I think she only travels in time through the Doctor. She has a very close relationship with The Doctor from the future. When he requires her to or when she feels the needs, she will travel back in time to one of his previous incarnations. In terms of her relationship with the Doctor right now she has travelled back into his past, but it’s also her future… It’s a little complicated!”

Why has she tracked down the Doctor now?
“In this particular episode she has been in prison quite a long time. She is allowed to leave prison under guard of some soldiering clerics. They’re basically there to make sure she doesn’t escape. She’s being used as an archaeologist to confirm whether a piece of art – a Weeping Angel which is in a collector’s hands – she believes it’s a weeping angel rather than just a sculpture and she needs the doctor to confirm this. A Weeping Angel is a statue-like creature first seen in 2007 epsiode Blink. In that episode it zapped people back in time.”

“She has met this Doctor before, although he hasn’t met her yet in his incarnation, except that he remembers when he was David Tennant. He remembers seeing her die – so he knows her future. He knows the bit she doesn’t know – God it’s so complicated! She has a blue diary she takes everywhere and that’s her map of their relationship – all the times they have met. So she has all the incarnations of the Doctor, all the images of his faces in this book, and all the adventures they’ve been on already in this book, but he’s not allowed to see.”

In the Library episode River Song whispered something to the Doctor – do we find out what that was?
“We don’t know what she whispered, except that she tells him his real name. And there’s only one person he’s ever told his name to, or would ever be prepared to tell his name to. That’s why in that episode he was so shocked, because he realised what his relationship to her was or will be in the future.”

Do you know more than we do? Have the writers tipped you off as to their future?
“Steven Moffat tells me a little bit. But to be perfectly honest it’s amazing. When we did Silence in the Library and I saw the book, it was beautiful and amazing, but I just thought it was a list of random things. But he’d already got it all planned. One of the first ones I name when I’m talking to David Tennant in Silence in the Library, I say: ‘OK, where are we, what have we done? Have we done the crash of the Byzantium, etc’ and he looks at me like I’m crazy. Well these two episodes now are the Crash of the Byzantium. So he has got all these amazing threads in his head. I don’t know whether he did write that down and then decided to use it for this one, but knowing Steven he had it all planned, because he is a computer in that respect, quite extraordinary.”

Does that affect how you play the character?
“When I read these two episodes I thought I knew who she was. Firstly, I thought I’d died, but I hadn’t. Or I hadn’t yet! But in these episodes, very teasingly she’s been in prison for murder, but we don’t know who she’s killed – although I have my suspicions – and she’s been there for a long time, six years. So suddenly I’m learning another side of my character I didn’t know before.”

When you heard Steven Moffat was taking over did you know you’d be back?
“No, I didn’t think I’d come back at all! But again when I read the script it made total sense how I could come back.”

What stunts did you do?
“I had to do some wire work and fly through space wearing Christian Louboutin
shoes and carrying a handbag. I loved it and now I want to appear in Chinese
martial arts films or fight with a light-sabre like they do in Star Wars!”

Were you a fan of the show?
“I grew up watching Doctor Who, as I think every child in Britain did. When
it was revived I was living in America, so I didn’t really know anything
about it until I was asked to be in it. I remember reading the script,
crying, and thinking: ‘If I am having this response, then I should do it’.”