From BBC Doctor Who
The Press Release confirming the news was released today and reads:
Mother and daughter Dame Diana Rigg and Rachael Stirling are set to star side by side in the BBC Wales drama Doctor Who, the first time the pair have ever worked together on screen.
Character details remain under wraps, but the episode penned by Mark Gatiss will see Dame Diana and Rachael recreate their off-screen relationship on-screen, as they play a mother and daughter with a dark secret.
Starring alongside the Doctor, Matt Smith and new companion Jenna-Louise Coleman, the episode will air on BBC One in 2013 and is directed by Saul Metzstein. Filming begins this week (2 July) at Roath Lock Studios in Cardiff.
Dame Diana Rigg, who will play a Yorkshire local, said: “The first time Rachie and I will be working together is on an episode of “Doctor Who” specially written for us by Mark Gatiss. How lucky is that?”
Rachael Stirling, on working on Doctor Who, said: “What joy. I am looking forward to the madness of Doctor Who enormously. Mark Gatiss has written a gift of a script and an on-screen relationship between Ma and I that is truly delicious. We have never before worked together because the offers have not been tempting, but when such a funny and original script comes through you know the time has come.”
Steven Moffat, executive producer and head writer on Doctor Who, said: “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!"