This chapter explores the idea that symptoms of trauma often appear only after a substantial length of time following the ‘original’ experience and how this led Freud to develop his theory of Nachträglichkeit. It begins with a discussion of Freud’s basic theory and then explores how this has been taken up within the framework of French psychoanalysis, with a particular emphasis on Laplanche’s concept of ‘afterwardsness’ within the context of his broader theory of ‘childhood seduction’ and Lacan’s use of the concept in the context of his theory of language and the drive. This is followed by a broader examination of the idea of ‘reverse causality’ in relation to Nachträglichkeit and trauma, and how this relates to wider questions of temporality and history. This is illustrated using the examples of Miller’s concept of ‘hystory’, Langer’s idea of ‘trauma time’ and Caruth’s idea of Nachträglichkeit as history. The chapter concludes by arguing that Nachträglichkeit is essentially a failed attempt to give meaning to trauma.