 In the 63rd of the series based on the Clarence E. Mulford character, Hopalong Cassidy (William Boyd) is working on a counterfeiting case for the government and, with his two pals California Carlson (Andy Clyde) and Lucky Jenkins (Rand Brooks), enters a town where they meet Nora Murray (Elaine Riley) and her brother Sid (William Leicester), who have come to claim the "Silver Belle" mine. The brother is killed by the gang led by Ora Mordigan (James Craven), and Cassidy discovers a lost mine where the gang has been holding John Murray (Herbert Rawlinson), Nora s father, a prisoner and forcing him to print the bogus money.