The value of Professional Learning Networks (PLNs) for school and system improvement is widely acknowledged in education research and policy. Still, the question of how learning happens for teachers and education leaders involved in PLNs remains largely unanswered. Moreover, little research exists on the increasing number of international networks for professional learning developed among education systems globally. This case study explores one such network, which we identify as a Global Learning Network (GLN), the ARC Education Project. ARC describes itself as a self-funded network of policymakers, scholars, and system leaders from a range of national and state-level systems with a shared commitment to equity, excellence, wellbeing, inclusion, sustainability, democracy, and human rights. Employing content analysis, we analyze observational notes and materials from ARC summit meetings, joint statements issued by ARC systems, membership records, and other key ARC documents. We draw from Rodway and Farley-Ripple's (2020) application of social network theory to examine this GLN as a relational space, given the challenges of global collaboration. We consider five key components of PLN efficacy: collaboration, sense of purpose, reflective professional inquiry, leadership, and boundary crossing. Specifically, we interrogate how the boundedness of ARC's membership mediates opportunities for the construction of new knowledge in the network. We conclude with implications for professional learning in global networks.