From an academic perspective, risk and uncertainty are separate and distinct. Risk is measurable (and hence manageable), uncertainty is not. From a practitioner perspective, those working within banks seek to show that what they are doing is managing risk on behalf of their shareholders and clients. The object of this research is an analysis of emails and other documents related to the bankruptcy of Lehman Brothers, with the aim being to explore how concepts of risk and uncertainty were discussed during the financial crisis, and how the boundaries between what might be considered 'risky', and what might be considered 'uncertain' became blurred and malleable. I will show that, from a practitioner perspective, there is a desire for risk to be objective, measurable, and omnipresent. At the same time, during periods of crisis there may be a belief (albeit nascent and submerged) that what is, in fact, being encountered, is uncertainty. This can be seen both in terms of archaeological layers of meanings and understandings at points in time, and in genealogical changes in these understandings over (relatively short) periods of time. However, utilisation both of networks of power, and of tactics such as framing and projection and diversion of blame, may be utilised in an attempt to cleave to previously accepted understandings, and to avoid acceptance of disruptions and discontinuities. Resistance to accepting the fact that discourse by itself cannot change a desire into a belief (either in oneself or others) is strong and widespread. Unless and until there are significant changes in culture, expectations, and rewards within banks, there is no reason to believe that this will change.