Synopsis by Hal Erickson
Had Madame Sphinx been made at Fox, chances are that Theda Bara would have essayed the title role. Instead, the film was made by Triangle, so the leading character was played by that studio's "house vamp" Alma Rubens. The film gets off to a colorful start, as the body of a wealthy man is found in his palatial home. The police immediately launch a search for the murderer, with the trail leading to the Latin Quarter of Paris. Here we meet Celeste (Rubens), known as "Madame Sphinx" for her refusal to speak to anyone or to reveal whence she has come. It could be that Celeste knows who committed the murder; it could also be that she pulled the trigger. And if that were actually the case, Madame Sphinx would have been over before it began; besides, this was a "murder mystery," and there is nothing mysterious about the top-billed actress turning out to be the killer.