Lure of Ambition (1919)

Poor Olga Dolan works as a public stenographer at a fashionable New York hotel. After she charms the Honorable Cyril Ralston and introduces him to her uncouth father and squalid home, Ralston persuades her to accept a suite of rooms in a hotel, promising he will marry her "some time." When Ralston returns to England, Olga vows revenge. She goes there working as the secretary to Lady Constance Bromley, and once there, learns that Ralston is her employer's son and also that he is married. Interested in the Duke of Rutledge, Olga makes Ralston introduce her to him. After Ralston becomes obnoxious in his advances, Olga becomes the duke's private secretary, impressing him when she flirts with a Spanish diplomat to make him sign some papers. When the duke's insane wife escapes from her secluded room in the castle, Olga stops her from killing the duke. The duchess' subsequent fatal heart attack brought on by intense jealousy allows Olga to marry the duke.