The best kind of mystery - one that plays its tricks on the audience as well as the characters. The numerous twists and turns are difficult to see coming, but don't feel contrived, and the story resolves itself by the end. It's entirely due to the strength of the two legendary actors, who play their roles convincingly and make the dialogue-heavy, written-for-the-stage script involving and interesting. The baroque-esque score and wonderfully inventive set only adds to the whimsy. A real old-fashioned film.