The proliferation of crises facing organisations is challenging how individuals make sense and respond to their new environments. This research investigates cognitive shifts in both leaders and followers in response to a cumulative crisis to ascertain the fluctuations in achieving cognitive consensus within a single case study firm. Cognitive vision formation theory and followership theory are integrated to account for the role of both leaders and followers throughout the crisis. 91 cognitive maps of leaders and followers were elicited during three phases of data collection over a four year period and analysed following a standardised procedure to explain how and where consensus was formed. Distance ratios are calculated to measure within and between group consensus and cognitive shifts. This research makes several key and original contributions to knowledge. First, during the initial stages of responding to a crisis it is the followers that are the locus of consensus rather than leaders and subsequently the cognitively diverse leadership teams converges towards follower teams which builds consensus as the crisis first unfolds. Second, following the initial stages, a bottom-up diffusion of consensus process is observed with middle-managers emerging as the locus of consensus between the middle and latter stages. Third, the inclusion of a midpoint in data collection provides fresh empirical evidence that the scope of cognitive consensus fluctuates rather than builds over a sustained period of time. Fourth, this fluctuation requires cognitive shifts in individuals which are detected as being initially higher in leaders than followers during responses to the crisis. Fifth, preliminary empirical evidence demonstrates that degree of cognitive shifts are also greater over a longer period of time than in the initial response to the crisis. Finally, a theoretical framework is developed to map the four different types of cognitive shifts individuals experience during a cumulative crisis. The thesis concludes with a call for future longitudinal multi-level research to further investigate the antecedents of cognitive shifts and empirically test the theoretical framework. Additionally, more attention is now required into the strategic role of followers and middle managers during a crisis