The year is 1910. Sigmund Freud and his heir-apparent, Carl Jung, are changing the way we think about human nature and the mind. Twenty-two year old Toni Wolff enters the heart of this world as Jung's patient. His wife, Emma Jung, is twenty-six, a mother of four, aspiring to help her husband create the new science of psychology. Toni Wolff's fiercely curious mind, and her devotion to Jung, threaten this aspiration. Despite their passionate rivalry for Jung's mind and heart, the two women often find themselves allied. Born of aristocratic Swiss families, they are denied a university education, and long to establish themselves as analysts in their own right. Passionate and self-educated, they hunger for another intellectual woman with whom to explore the complexities of the soul, the role of women in society, and the archetypal feminine in the affairs of nations.Their relationship spans 40 years, from pre-World War I to the dawn of the Atomic Age. Their story follows the development of the field of psychology, and the moral and professional choices of some of its major players. Ultimately, Toni and Emma discover that their individual development is informed by both their antagonism, and their common ground. They struggle to know the essence of the enemy, the other, and to claim the power and depth of their own nature.