Bodyguard actress Anjli Mohindra is to guest star in the return of Doctor Who.
Mohindra, 29, who starred as Nadia in hit drama Bodyguard and in Doctor Who spin-off The Sarah Jane Adventures, takes on a new character.
Laura Fraser, 43, will also guest star in a separate episode and lists The Missing and Better Call Saul to her name.
Doctor Who will return to TV screens on New Year’s Day with a two-part episode called Spyfall.
Jodie Whittaker, the 13th Doctor, will again be joined by Tosin Cole as Ryan, Mandip Gill as Yaz, and Bradley Walsh as Graham.
Mohindra said: “As a huge fan of the last series, it’s a bit of a dream come true …
“There’s something undeniably special about Jodie’s Doctor, and to be bringing some terror to the joint was rather fun indeed.”
Fraser said: “I love this episode and couldn’t resist playing such an intense character.
“I watched Doctor Who every week as a child, so it was a massive thrill to be asked to take part in such an iconic show.”
Executive producer Matt Strevens said: “ We’ve wanted to work with them since we started and have found the perfect characters for them to show off their talent and range – both formidable in very different ways.”
It was previously announced that Stephen Fry and Sir Lenny Henry will also appear.
TV bosses have promised “blockbuster action”, saying the Doctor is “well and truly back with a bang”.