Emergency care in large urban hospitals across the country is in the midst of major redesign intended to deliver quality care through improved access, decreased wait times, and maximum efficiency. The central argument in this paper is that the conceptualization of quality including the documentary facts and figures produced to substantiate quality emergency care is socially organized within a powerful ruling discourse that inserts the interests of politics and economics into nurses' work. The Canadian Triage and Acuity Scale figures prominently in the analysis as a high-level organizer of triage work and knowledge production that underpins the way those who administer the system define, measure and evaluate emergency care processes, and then use this information for restructuring. Managerial targets and thinking not only dominate the way emergency work is understood, determined, and controlled but also subsume the actual work of health-care providers in spaces called ‘wait times’, where it is systematically rendered ‘unknowable’. The analysis is supported with evidence from an extensive institutional ethnography that shows what nurses actually do to manage the safe passage of patients through their emergency care process starting with the work of triage nurses.