While visiting the country of Argovinia, Katherine Dereham, a young English woman, falls in love with Prince Anton, who offers to make her his mistress. Wounded by his insolence, Katherine returns to England upon the death of her father. When World War I breaks out, she begins to see her father's doctor, Garth Vincent. After the war, Katherine has a nervous breakdown, and Vincent nurses her back to health. Upon her recovery, Katherine visits a seaside resort where she again meets Anton. He renews his pursuit of Katherine, thus forcing Vincent to acknowledge his love for her. Vincent offers her a proposal of marriage and Katherine accepts.