Judex (1916), and Tih-Minh (1918). (Edward Gorey, who enthusiastically recommended Feuillade to me, thought that the serial Barrabas (1919) was the "greatest movie ever made"; unfortunately, I've never been able to see either it, the second series of Judex or 1922's Parisette.) It is understood that Feuillade came from a conservative, Catholic background and had a military career, which offers no explanation at all as to why he would suddenly start in filmaking around 1905 and proceed with such explosive productivity to make works with proto-surreal imagery and strage plots that persistantly resist the conventions of bourgeois morality like his suspense serials, in which the villains rapidly become your heros. The criminal gang of Les Vampires or the outside-the-law heroes of Fantômas or Judex certainly inspire the audience's allegiance more firmly than their opponents in the establishment. There is an anarchic tendency here that famously got Les Vampires banned for a time, but also is a powerful source for every masked film hero to come.
IMDB offers up this plot summary for Tih-Tinh: