Incidents featuring ambiguous or unexpected events make people’s sensemaking efforts visible (Landgren 2005a), which means that the emergency response domain should provide fertile territory for the study of the phenomena. This chapter sets the context for the activity that is studied in this book. Whilst the observations were conducted in UK police settings, this chapter explores these in terms of the concept of C2. Ultimately, we propose that different C2 structures might support different forms of sensemaking activity.