In the years between 1825 and 1841, California, a province of Mexico, is torn by internal strife. While France and Russia attempt to gain a foothold in the rich land, many of California's people hope to be annexed by the United States, a development that they believe would bring them freedom. One of these Californians is Don Arturo Bordega, who rides toward la Reina de Los Angeles with the intent of buying defensive weapons from gunsmith Sam Lawrence. Arturo and his servant Juan are pursued by bandits, but they manage to elude their attackers and arrive safely in Los Angeles. The don and several other Californians, including the ambitious and greedy brothers, Ernesto and Fredo Brios, plan to discuss U.S. interest in the territory with Capt. John C. Fremont at a ball that evening. As Fremont approaches Los Angeles, however, the same bandits attack his coach, killing everyone but him. At the ball that evening, Don Ernesto, who hopes to be named governor of California, seems surprised when Fremont arrives for the meeting. His head wrapped in bandages, Fremont explains that the U.S. has no intention of becoming involved in Mexico's internal conflicts. Annexation would depend on proof that the majority of Californians would support such a move. Following Fremont's departure, Don Fredo hints that Arturo is a threat to their plans, whereupon Don Ernesto challenges Arturo to a duel for having insulted him earlier that day. Their furious sword fight ends in Don Ernesto's death, but at that moment, the bandits, led by José Martinez, attack the gunsmith's shop, killing Sam and stealing his firearms. Sam's beautiful daughter Julia is devastated by her father's murder, and when she learns that Arturo plans to infiltrate Martinez's gang, she follows the don on horseback. Attracted to Julia and concerned for her safety, Arturo orders her to return home, but she, declaring that she is an excellent shot, is determined to avenge her father's death and joins him in pursuit of Martinez. They arrive in Monterey just in time to learn that the Brios brothers hired Martinez to steal the guns. Dressed as a poor laborer, Arturo robs Martinez of his payment and returns to Julia with the bandit in close pursuit. There he feigns admiration for Martinez, calling him the "friend of the people" for opposing the "gringo" takeover of California. Martinez is flattered and accepts Arturo and his "wife" Julia into his gang. The bandits raid and burn the ranches of many of the California landowners who favor annexation, but at each attack, Arturo secretly leaves the same note: "Be of courage." At Fort Ross, Don Fredo meets with Count Alexander Rotcheff and Princess Helena de Gagarine, the niece of the Russian czar. Because Don Fredo has paid Martinez to intimidate the landowners and secure a cache of guns, he predicts that there will be no trouble when the czar's soldiers place California under Russian protection. In return for his assistance, the Russians will make Don Fredo governor of the territory. Julia attempts to flee the Martinez gang in order to warn the local citizens of the takeover plans, but she is caught. Arturo is whipped for her transgression, after which she grabs a gun, reveals her true identity, and shoots Martinez. Julia then rides to the governor's office for help, while Arturo heads for Don Fredo's hacienda just ahead of the remaining bandits. Julia learns that the Mexican governor has no troops to defend the province from the impending Russian attack, but some of the citizens band together and head for the hacienda. Meanwhile, Arturo sneaks into Don Fredo's house and kills the don in a brutal fight. Julia and her group of citizens capture the Russian princess, but the attacking Russian soldiers outnumber the Californians. During the battle, Arturo and Julia load a powder keg onto a wagon, light the fuse, and push the wagon toward the Russians, where it explodes. With the Russian threat removed, Julia and Arturo plan their future together.