1115, Germany. Young Hildegard is sent to the Abbey of St. Disibod in the Rhineland as her parents' gift to the Church in accordance with a custom known as the tithe. Hildegard has a deep love of nature and a knowledge of herbal healing, and she hopes to purse medical studies at St. Disibod. But no sooner does she settle into her new life than she finds out that as a girl she will not be allowed to attend the monastic school or have access to the abbey's library; instead, she must stay at the women's convent.

It might seem that Hildegard's dreams have quickly come to an end. Yet she refuses to be sidelined. Against fierce opposition from Prior Helenger, the hostile head of the monks' cloister, she finds another way to learn–by securing an apprenticeship with Brother Wigbert who runs the infirmary and is in dire need of a capable assistant. Under his supervision, she begins to train as the abbey's first female physician.

When Hildegard's reputation starts to spread throughout the Rhineland, Helenger's persecution escalates as he fears losing control over the women's community. But that is not the only challenge she must grapple with. She has developed feelings for Volmar, a fellow Benedictine novice, that force Hildegard to re-examine the fundamental assumptions she has made about her life.