The secret's out.  Miss Marple has a secret identity.

I was watching Robin Hood: Prince Of Thieves (1991) and noticed the the character of Mortianna looked familiar.  For those who don't remember, Mortianna was the scheming witch to whom the evil Sheriff of Nottingham goes for advice.  She's a very wicked looking character.  But somehow she looked familiar.  Where had I seen her before?

Finally it came to me.  She played Miss Marple on the PBS Mystery! series adaptation of the Agatha Christie books.  (I realize I'm one of the few who know of Miss Marple, but I'm not ashamed to admit it.)  I wasn't completely convinced until I confirmed it on IMDB.  Both characters were played by Geraldine McEwan, a British actor born in 1932.

I believe I had only seen this movie once, when it first came out 18 years ago.  I had forgotten a lot of the story, but it was really good.  And of course I was glad to see James Bond make a cameo appearance at the end of the movie!  "The name's Hood, Robin Hood."