"Dorothy L Sayers Mysteries", "Gaudy Night" starring Edward Petherbridge & Harriet Walter.

The Beeb did the three "Peter & Harriet" stories from the Lord Peter Wimsey books in 2002. "Gaudy Night" is set in Oxford before WWII. It must have a young man lounging in flannels in it somewhere.

I tried to pop my copy in and find one to 'cap for you, but my DVD drive insists the disk I just put in there isn't there. (stupid machine!)