Organizations increasingly find themselves contending with circumstances that are suffused with dynamic complexity. So how do they make sense of and contend with this? Using a sensemaking approach, our empirical case analysis of the shooting of Mr Jean Charles de Menezes shows how sensemaking is tested under such conditions. Through elaborating the relationship between the concepts of frames and cues, we find that the introduction of a new organizational routine to anticipate action in changing circumstances leads to discrepant sensemaking. This reveals how novel routines do not necessarily replace extant ones but, instead, overlay each other and give rise to novel, dissonant identities which in turn can lead to an increase rather than a reduction in equivocality. This has important implications for sensemaking and organizing amidst unprecedented circumstances.