This work investigates the complex psychological processes of a patient undergoing long-term psychoanalytic treatment to understand the development of the self and the boundaries of personal identity. Marion Milner, a British psychoanalyst and artist, documents her clinical observations over a twenty-year period with a single patient. She utilizes her background in both clinical practice and creative inquiry to explore how the patient navigates the transition from a fragmented sense of self to a more integrated existence. The text serves as a detailed record of the therapeutic relationship and the evolution of the patient's internal world.

Experts in the field of psychoanalysis frequently cite this text as a foundational study on the nature of the self and the therapeutic process. Readers often note the dense, clinical nature of the prose, which provides a rigorous look at the complexities of long-term patient-analyst interaction.