So.. I was watching this movie Atonement. (A good movie), and I went to IMDB to look into something and there was this name: Harriet Walter. Immediately, some bulb went off in my head, and I remembered Harriet Vane - Harriet Walter. Here is a link to do the same to your memories : http://www.geocities.com/gregorym101/bbcwimsey_tv_peth.html
Enjoy your trip down memory lane.