14. The Master Mytery (1921)
Harry Houdini (yes, THAT Harry Houdini) plays a Justice Department agent named Quentin Locke who must investigate a powerful cartel protected by a robot. Much of this 15-chapter serial was lost due to nitrate rot, but enough remains to see quite a few legitimate Houdini escapes. Watch it if you can, but be ready for some slow-moving action.
Estimated chance you've seen this one: 3%