Intelligence analysts pore over myriad sources to identify key facts, make sense of them, and use that “sensemaking” to inform mission-critical action. Often these operations are conducted 24/7 with analysts working in shifts. To understand these processes in situ, we conducted interviews with seven former and current United States intelligence analysts. We develop theory and advance a descriptive model of shift handover processes in this domain, which takes into account sensemaking, the communication process, and the features of big data. Our qualitative analysis reveals the following tensions analysts face in shift handovers (1) narrowing versus broadening one’s own sensemaking, (2) sensemaking versus encoding for the subsequent analyst, and (3) trusting versus validating the prior analyst’s sensemaking. In addition, we describe several practical takeaways.