Wild Bill Hickok and Calamity Jane try to stop foreign agents from taking over the West.
During the Civil War, Nicholas Tower, a European agent, comes to America to organize a fifth column and seize western territory. Tower enlists Morrell, a notorious guerilla, to foment unrest so that he can seize control of California's fabulous wealth by forcing the state to break away from the union. Young Bill Hickok, a relay station attendant at the Waddell Freighting Company, distinguishes himself by overpowering some of Morrell's raiders and earns the name of "Wild Bill." Bill is in love with Louise Mason, whose sympathy to the cause of the South has wavered since her engagement to Bill. New uprisings of Morrell's raiders result in Bill being ordered to personally escort a shipment of gold. Fearing another raid, Bill arranges for the gold to be secretly transported by horse wrangler Gabby Whitaker and his niece, Calamity Jane. Bill confides the plan to Louise, who, worried about Bill's safety, seeks reassurance from Tower. Learning that the gold is to be transported by Gabby, Tower sends Morrell to steal the shipment and then convinces the townfolk that Bill is behind the raids. Louise, realizing that she has been double-crossed, accuses Tower of duplicity. Meanwhile, Bill searches Tower's private papers, hoping to link him to the Confederate cause, but all he finds is a note signed by a man named John Wilkes Booth. Bill is arrested and jailed for the robberies when word arrives that Lincoln has been assassinated by John Wilkes Booth. Remembering the note he found among Tower's papers, Bill breaks out of jail and persuades the sheriff to follow Tower, who has sold his business and is leaving town. When Tower sees the posse, he tries to escape, but Bill catches him and finds the stolen gold hidden in his wagon.
