In Mexico, a humble peon has great difficulty retaining his small farm because of the greediness of those controlling the government. While he is in another town, two federal officials search for loot in his cottage and attack his two sisters. The eldest, lame from birth, shoots herself rather than succumb to their lust. Her fourteen-year-old sister loses her mind and dies after telling her brother what occurred. The peon vows vengeance and is branded an outlaw by the frightened officials. After he escapes from jail with the help of an old family servant, he is aided in eluding his pursuers by Americans traveling in a covered wagon. Years later, the outlaw, now the commander-in-chief of the Constitutionalist Army, wins many victories and kills one of the officials who attacked his sisters. When he learns that the Americans who helped him are in trouble, he leads a cavalry charge to rescue their wagon train from being attacked by revolutionists. He recognizes one of the attackers as the other official and is about to exact vengeance as the film ends.