A Spanish nobleman becomes a masked outlaw by night to battle a local tyrant.

In the early 1800s, when Diego Vega, one of the best swordsmen in all of Spain, is unexpectedly summoned home to California by his father, Don Alejandro, he returns to find that his father has been deposed as alcalde and the peasants crushed beneath the yoke of tyranny under Don Luis Quintero and his soldiers, who are led by the sword brandishing Captain Esteban Pasquale. With the odds against an uprising because of the sheer number of soldiers under Pasquale's command, Diego becomes the scourge of the oppressors by acting as the masked bandit Zorro by night while impersonating a foppish dilettante by day. As Zorro, he falls in love with Quintero's beautiful niece Lolita, while as Don Diego, he flirts with Quintero's conceited wife Inez, thus earning the ire of Pasquale, her other suitor. When Zorro orders that Quintero return to Spain and appoint Don Alejandro as his successor, Pasquale cleverly proposes an alliance between the Vega and Quintero families through a marriage between Diego and Lolita. At first repulsed, Lolita embraces Diego after she discovers that he is the dashing Zorro. However, Diego's masquerade is exposed when his accomplice, Fray Felipe, is arrested by Pasquale and Diego challanges the smug captain to a duel. When Diego kills his opponent, he attracts the suspicion of Quintero, who arrests him and sentences him to death. As Fray Felipe and Diego await the firing squad, Diego outwits the guard, breaks out of jail and leads the peasants and caballeros in a rebellion against the soldiers. With Quintero and his men defeated, Don Alejandro takes over as alcalde, and peace is restored to the village of Los Angeles.