The goal of this article is to provide an account of the difficulty, in the present, of reconstructing a punk event that took place 40 years ago. I will use this undertaking as the basis for reflecting on the larger conceptual stakes (ideas and concepts) that are illustrated by this specific event from the past, the Brockwell Park Festival, London. I played bass at this event in Strawberry Switchblade, a female-led cult post-punk band. A cold case is used here as a metaphor for this reconstruction; the larger conceptual stakes are the ‘mystery’ to be investigated. This in turn enables me to frame my account of that day from the past in terms of how it functions within punk and post-punk culture and scholarship. There was a lot of fun, energy and some ‘aggro’ (i.e. violent or threatening behaviour) at this event. I present an autoethnography, reviews from the time and various first-hand accounts of this particularly tense punk and post-punk event, i.e. my cold case, so that I can examine the significance and the importance of returning to the past and unpicking the memories and myths of subcultural experience. This is followed by a discussion of the larger conceptual stakes: memory, subcultural memory and myth; ‘tribes’; discomfort and uncertainty.