Sombra, the Spider Woman is the feature-film abridgement of the 1947 Republic serial The Black Widow (which explains why a number of the listed actors had died by this film's listed year of release). The formidable Carol Forman stars as Sombra, whose fortune-telling establishment serves as a front for a vast criminal empire. Making things trickier for hero Steve Colt (Bruce Edwards) is the fact that Sombra is a master (or mistress) of disguise. Colt and plucky girl reporter Joyce Winters (Virginia Lindley) try to prevent Sombra from stealing the plans for a revolutionary atomic rocket engine. This is one serial in which the male actors are thoroughly overshadowed by the female leads.
by Hal Erickson synopsis