In the tradition of 20th Century Fox's semi-documentary "Now it can be told" films, Monogram Picture's "A" division Allied Artists came up with Southside 1-1000. The U.S. Secret Service goes after a gang of counterfeiters, whose engraver (Morris Ankrum) has covertly constructed his plates while in prison. A federal agent (Don DeFore) poses as the counterfeiters' contact man in order to purchase enough bills to incriminate the gang. The final fight-to-the-death scene was filmed aboard Los Angeles' "Angel's Flight," a cable-car service dangling 40 feet above the ground. Southside 1-1000 was based on a true story, as narrator Gerald Mohr points out on several occasions.