I was just watching the movie BRITISH INTELLIGENCE, an adaptation of a play called "The Three Faces," at Veoh. Boris Karloff starred as the main villain, von Stringler/Schiller/Valdar who is trapped by the lady listed as his co-star. The movie was made by Warner Brothers, apparently for the British market, and is now in the public domain. Enjoy!
I do like this film - nice to see Karloff NOT as a mad scientist. Of course, with the British Horror film ban, many of the Universal horror stars had to find other genres to work in.