In Denmark many illegalised migrants are subjected to open-ended detention at ‘departure centres’. Based on qualitative data collected during 2017–2022, this article examines instances where detention leads to separation of mixed-immigration status families. Drawing on concepts of deportability, detainability, and in/visibility the article argues that departure centres constitute border spectacles, which simultaneously render people hyper-visible as ‘illegal’, unattached individuals about to depart and invisibilise them as parents and spouses. Detention in departure centres disturbs rather than interrupts intimate relations, and it enables mixed-status families to resist separation through tactics of travelling on, moving nearby, or commuting. These tactics produced by the return system increase the vulnerability of illegalised migrants and amplify the pain of deportability. In this paper I propose the term ‘pathopolitics’ to enable the description and analysis of the power directed at illegalised refugees and migrants in Denmark. I argue that the practice of separating families should be understood as one of several pathopolitical power techniques used to induce return, a technique that works through temporal and spatial measures, and one that inflicts high human costs on illegalised migrants and their families.