2013 will be a big year for Doctor Who. Not only will the good Doctor find himself working with a brand new companion played by Jenna-Louise Coleman, but the good Doctor will also teaming up with a fellow British icon. According to BBC News, Dame Diana Rigg is currently working on an episode of the series, which is celebrating its 50th anniversary next year. Riggs' name might not jump off the screen at most U.S. readers, her television identity as Emma Peel in The Avengers from 1965 to 1968 cemented her position in television history. Rigg is also known for portraying the woman who married James Bond in George Lazenby's one and only outing as the character in 1969's On Her Majesty's Secret Service.

Rigg is joined in the episode by her daughter Rachael Stirling, an actor in her own right who has appeared in UK shows like Tipping the Velvet. The pair, who have never appeared in the same project together, will play a mother and daughter team "with a dark secret" according to Who executive producer Steven Moffat.

Both Rigg and Stirling credit their participation in the episode to the script by Mark Gatiss who has written some of the series' more memorable episodes like "The Unquiet Dead" and "Night Terrors" as well as many Sherlock episode. "Mark Gatiss has written a gift of a script and an on-screen relationship between Ma and I that is truly delicious," Stirling said. "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."

An air date for the episode has yet to be announced, but the actual 50th anniversary for Doctor Who will take place on November 23rd.