Of the various forms that the matter of time assumes in analysis, Nachträglichkeit represents Freud's first intuition on the subject. The focus of this article is directed toward the specific temporal dimension that the concept of Nachträglichkeit expresses, and how that dimension, which overturns linear time, is expressed in clinical work. The concept of Nachträglichkeit is approached from a theoretical point of view, tracing back the role and development that this notion has had in psychoanalytic Freudian and post-Freudian thinking. The goal of this article is to demonstrate how Nachträglichkeit represents the unique temporal movement of the analytic session and the characteristic positioning of the mind of the analyst at work. Three clinical examples are presented. The analytic scene is formulated as occurring in two times, and through the working through that takes place, patients can recover the enigmatic 'remainder', which is consequently traumatic and which has compulsively accompanied them through the various times of their existence. Nachträglichkeit, as a non-linear temporality, introduces a unique dimension into the clinical work that influences listening to and interpretation of the material. The recognition of that (trauma, infantile sexuality, non-linear temporality) has consequences for the analyst's way of working in session and on the interpretation of clinical material, as I will try to show through my theoretical exposition and clinical examples.