Call the Midwife star Jessica Raine has spoken about her experiences working on the new series of Doctor Who.
Raine will guest in the upcoming run of the BBC show as a character called Emma Grayling.
Speaking to the Radio Times about her stint, Raine said: "[It is] very different from Midwife. On Doctor Who it was all mind machines and strobe lighting.
"But it was a magical experience and something I was very happy to do. It's a very different character and genre - you have to throw yourself into it and take it very seriously.
"I hadn't realised what an institution Doctor Who is. I got offered the part and didn't think that much about it. Then you go on set and you see this blue police telephone box, and suddenly the weight of what you're doing hits home."
She also praised Doctor Who's Matt Smith for the "darker edge" he has brought the long-running sci-fi series. "He's a brilliant actor. He has a very long career ahead of him," she said.
Raine's episode is expected to be titled 'Phantom of the Hex'.
