In the early 1800's, after California became a territory of the newly born Republic of Mexico, many sought to take over the rich land for themselves. In 1825, Mexican Marcos Zappa comes ashore on the coast of California from a pirate ship under the command of Captain Bardoso and is taken to meet Pedro Garcia, who tells him that he knows that Marcos has been found guilty of disloyalty to the Republic and banished into exile. Marcos always wears a bandana across his forehead to conceal the spot where he was branded with the letter "R" for renegade because in California, he will be instantly killed if the mark is seen. Garcia, who intends to become emperor of California, blackmails Marcos into helping him, then buys him new clothes and sends him to meet his rival, José de Vasquez, leader of the party for the Republic in California. Marcos is to court de Vasquez's daughter Manuella and marry her, thus providing Garcia with direct access to the current ruler of California and enabling him to control de Vasquez by threatening to reveal that his daughter is married to a renegade. Manuella already has a fiancé, Miguel de Gandara, so Garcia orders Marcos to initiate a quarrel with Miguel and kill him. Garcia sends Bardoso and Luis, one of his henchmen, to accompany Marcos to the pueblo of Los Angeles, where Marcos and Bardoso go to a gambling house run by Anita Gonzales, who tries to seduce Marcos. When a fight breaks out among the gamblers, Marcos and Bardoso escape but are later spotted by soldiers. Marcos, who had met de Vasquez, Manuella and Miguel earlier when he helped foil a staged holdup of their carriage, receives an invitation to a fiesta at the de Vasquez home, where they will raise the flag of the Republic for the first time in California. Garcia, whom Manuella previously rejected as a suitor, is also invited. Manuella shows interest in Marcos, finding him mysterious, and he tells her that, under different circumstances, he may be able to say that he loves her, then shows her the brand mark. When Marcos later falls from a horse, he insists that he only be attended by Father Juan, a Franciscan priest. Garcia gives Marcos a deadline by which he must become engaged to Manuella or be exposed as a renegade. Garcia also orders Bardoso to bring his pirates to attack Los Angeles, so that he, Garcia, can appear to save the population and enhance his plan to dominate the state. Manuella thinks that Marcos is involved with Anita, who is in league with Garcia, but Marcos swears that he is in love with her, Manuella. After Manuella visits Marcos in his room one night, her father accuses Marcos of bringing shame on his family and insists that they marry. At the wedding ceremony, Miguel challenges Marcos to a pistol duel, but Marcos shoots into the ground as Colonel Vega and his troops arrive. Vega confronts Garcia with Bardoso, whom he has arrested along with his men. Bardoso confesses that he had been ordered by Garcia to raid and loot Los Angeles. Anita identifies Marcos as a renegade, but Manuella states that she has known this for some time. However, Father Juan reveals a major surprise as he removes Marcos' "brand" with some wine and relates that, in Mexico City, after his Order had informed the government of a plot to take over California, they decided to send a secret emissary to investigate. Marcos was chosen and voluntarily accepted disgrace and exile so that he could join the pirates and discover the mastermind behind the plot, Garcia. Marcos and Garcia engage in a sword fight, and after Marcos kills him, Manuella and Marcos marry.