HANDS UP (lost serial,1918)

This was the film that made Ruth Roland a household name, and is one of only two silent serials to have two lead actors.  George Cheseboro was the original lead actor, but he was drafted into the Army and an actor named George Larkin took his place.  It's unclear how this was managed onscreen, but it was probably done through plastic surgery.  Ruth's character was Echo Delane, a reporter who turns out to be the the heiress to a ranch.  She has to evade the Native Americana who believe she's their princess and want to sacrifice her to her god to claim the ranch, though.  The MacGuffin here, as written by Gilson Willets, was probably a paper proving Echo's family's claim to the land.