Synopsis: A mysterious veiled woman arrives at a castle in Poland, pregnant, and dressed as a nun; she never removes her veil. After the birth of the child a French officer arives and takes the child away with violence. The back-story is related: Hermengilda was in love with Stanislaus, a French officer, and quarreled with him, whereupon he returned to the wars; Hermengilda became insane. His cousin Xaver (who wanted Hermengilda himself) kept her company. Hermengilda had a vision that she had married Stanislaus on the battlefield, and he had almost immediately been killed (this turns out to correspond to the time of Stanislaus's actual death). Her family is surprised that she is pregnant, and she goes to a convent, determined to spend the rest of her life mourning. Xaver eventually confesses that he is the cause of her pregnancy, having stood in for Stanislaus while Hermengilda was immersed in her vision. He commits himself to lifelong penance.