The novel imagines the lives of historical figures. Dr. Josef Breuer was a pioneering neurologist and one of the founders of modern psychology. His discovery of the role of the inner ear in regulating balance is referenced in the novel. Breuer is best known today for his treatment, together with his younger protégé Sigmund Freud, of Bertha Pappenheim, referred to pseudonymously in both men’s writings as Anna O. She exhibited a range of physical symptoms, including paralysis and loss of vision, and Breuer noticed that those symptoms seemed to lessen as she talked about them. Bertha’s conversations with Breuer and Freud later formed the basis for Freud’s early theories of psychoanalysis. Importantly, it was Bertha herself who coined the phrase “talking cure” to describe her treatment, and she also originated the term “chimney sweeping,” which both Breuer and Nietzsche use throughout the novel. A key contention of the book is that psychotherapy is always a collaboration between therapist and patient, and insufficient attention has been paid to Bertha’s own active role in the development of talk therapy.

Josef Breuer is 40 years old at the time of the novel. He has made two important scientific discoveries.