‘Do you want me to take over^'

This article is concerned with the in situ negotiation of epistemic primacy in the context of medical emergencies. It investigates the mobilisation of questions and positioning in the material space as mechanisms for claiming control and for co-constructing epistemic authority. We bring together two high-risk, high-pressure emergency contexts – obstetrics and major trauma – and show the patterns that emerged from a bottom-up interactional sociolinguistic analysis of the data. We draw on a corpus of approximately 400 questions from a sample of ten teams; we zoom in on the role of the institutionally defined team leader, while special attention is also paid to the ways in which institutional power asymmetries are negotiated across the team in leadership enactment. We discuss the typology of questions that emerged from our data on a spectrum from a not knowing (K?) to a knowing (K+) status. Our analysis demonstrates consistent patterns in displays of epistemic primacy, with team leaders raising most of the questions indicating a K+ status across contexts. Further, we show that verbal claims of epistemic primacy are conditioned upon team leaders’ positioning at specific material zones of the emergency room as an integral part of doing their role.