Mary Fuller, Marc McDermott, Charles Ogle, Barry O'Moore, Bliss Milford, Bigelow Cooper, William Wadsworth, Miriam Nesbitt, Harold M. Shaw
The forerunner of all serials, What Happened to Mary was a series of twelve monthly one reel episodes, each a complete entity in itself, revolving its immediate dramatic and melodramatic problems within the framework of a single episode and designed more for story and suspense situations than action.