Disguising herself as a masked bandit, Catalina, the ward of the governor of a Spanish province, avenges injustice, aids the poor, and plots a revolution. Hugh Winthrop, a young American who owns mines in the province, comes to inspect them and is kidnapped by Catalina, who suspects him of being an enemy of the people. He escapes but meets Catalina later at the governor's palace, where they are arrested for stealing state papers. Catalina escapes, and Hugh is sentenced to be executed. As he is standing before the firing squad, Catalina and her followers ride in and save him. The governor, who was responsible for many of the province's ills, is convicted; and Hugh and Catalina are united.