I recently had a chance to view "The Mystery of the Rocks of Kador", directed by Leonce Perret. It's one of the selections on the Gaumont Treasures DVD from Kino, and I believe that it was virtually unseen in the United States before now. Having some familiarity with movies from the early 1900's, I was still surprised by the level of sophistication that Perret brings to this film. It's an engaging four-reel crime story with a very satisfying resolution.
Perret plays the villain - a gentleman willing to do away with his cousin Suzanne and her lover in order to get his hands on her inheritance. It's interesting to see how the villain commits his crime, but the real charm of this movie is the "film within a film" that is used for psychological effect. I would never have expected this in a movie made in 1912. You have to see it to believe it.
Perret does a fine job as both actor and director. Some of the other acting is a bit over-wrought, but the story's pacing kept me entertained throughout. If you are familiar with other dramas of this period (works by D.W. Griffith or Urban Gad, for instance), you may want to see "The Mystery of the Rocks of Kador". You may be as surprised as I was.