Police investigations of major crimes are typically conducted in contexts where there is contested or ambiguous knowledge about what occurred and such challenges are also routinely faced in the investigation of missing persons. This article examines ways in which attempts to ‘manufacture certainty’ in missing persons cases are strongly informed by geographical notions of space and place. The article is structured around the key phases of police investigations, each of which involves the mobilization of different forms of geographical knowledge. In the first stage of ‘identifying and acquiring’ information, the process of search is structured by knowledge about the possible spatial behaviours of missing people often generated using spatial profiling techniques. In the second phase of ‘interpreting and understanding’, more nuanced accounts of what may have happened to a missing person are constructed as the police attempt to ‘place’ a person’s disappearance within a particular narrative based on their reading of the intelligence picture that emerges during the investigation. In the concluding phase of ‘ordering and representing’, the case to internal (senior police management) and external (relatives of the missing person and wider public) audiences investigators will often invoke a notion of ‘the end of the world’ referring not just to how they have defined the geographical limits of the police search if the person is still unaccounted for but also the boundaries of reputational risk and the proportionality of the police response.