And joining Rigg for her trip with the Time Lord will be her real-life daughter, Rachael Stirling, the BBC reports.
In an episode filming this week with series star Matt Smith and new companion Jenna-Louise Coleman, Rigg and Stirling will play a Yorkshire local and her daughter, who together share a “dark secret.”
“The first time Rachie and I will be working together is on an episode of Doctor Who specially written for us by Mark Gatiss,” Rigg noted. “How lucky is that?”
Stirling said that she and her mother have never worked together before “because the offers have not been tempting, but when such a funny and original script comes through you know the time has come.”
“Mark Gatiss has written a gift of a script and an on-screen relationship between Ma and I that is truly delicious,” added the actress, whose TV credits include BBC’s Women In Love and Tipping the Velvet.
As series showrunner Steven Moffat remarked, “Dame Diana Rigg, Rachael Stirling and a Mark Gatiss script — a combination of talents you could only get in Doctor Who! Frankly, I’m terrified already!”
UPDATE: For the uninitiated, Rigg’s long career has also included films such as On Her Majesty’s Secret Service, 1971′s The Hospital (for which she got a Golden Globe nod), the Hercule Poirot mystery Evil Under the Sun and The Painted Veil. On TV, she earned a pair of Emmy nominations for her turn as Emma Peel (and scored a win for the 1997 TV-movie Rebecca), played the title role in 1981′s telepic Hedda Gabler, starred in Bleak House and The Mrs. Bradley Mysteries and, most recently, was featured in the BBC miniseries The Last King. She is also a Tony Award winner, among other stage accolades.