Tracing the continuously changing dynamics between China and its quasi-independent capitalist 'special territory', Hong Kong, this paper brings together the under-recognised cross-border caregivers and over-recognised care consumers in the wake of multiple care crises, articulating how internal and international migration clashes in the borderlands crossed by various kinds of travelling mothers from the Mainland. With a focus on care as social practices and relations, it observes how the boundary between internal and international migrations shifts and multiplies as care is alienated, displaced, and commodified. To understand the mobility and multiplicity of borders, it adopts an integrated framework that links internal and international migration studies, and more importantly, attends to care. A transnational perspective on the dynamics of mobile, unpaid care labour, as they play out within the boundaries of the same, recently 're-integrated' country, further suggests that attention must be paid to the conceptual terrains and lived experiences of those who live and move in-between internal and international migration regimes, especially the invisible caregivers who frequently travel across borders.