California Conquest

[1] The film is set in the early 1840s, and deals with a conspiracy by native Hidalgo Californios to deliver the then-Mexican territory of California to the Russian Empire.

Don Arturo Bordega (Cornel Wilde) is part of the old Spanish nobility, and a vocal advocate for California's annexation by the United States.

It is subsequently revealed that the Brios brothers, Ernesto (Eugene Iglesias) and Fredo (John Dehner), have paid Martinez to violently oppose the movement advocating American annexation of California, as part of their plot to deliver California to the imperial domain of the Russian Czar (in exchange for a promise to appoint first Ernesto, and later Fredo, as the Russian colonial governor).

Martinez's men violently seize a quantity of rifles from gunsmith Sam Lawrence (Hank Patterson), in order to arm a force in support of the Russian conquest of California.

This invokes the wrath of his beautiful daughter, Julia (Teresa Wright), who winds up joining Arturo Bordega in his mission to infiltrate Martinez's bandit group, in order to foil their part in the scheme.