Aligned with the development of human capital, in-service teacher education is globally conceived as a key lever in economic development. However, teacher education is also a critically important process to leverage teacher political awareness and social justice. This article provides a socio-materialist account of continuous professional development (CPD) that recognises the transversality of objects, space and bodies as a rich and complex assemblage. Investigations into agential matter are of increasing research interest. The authors use collective biography that draws on their CPD work with teachers in Aotearoa/New Zealand, to provide a "new material" analysis of the multiplicitous nature of the agency of objects. Although agency in education is predominantly theorised in humanist terms, this article gives consideration to the co-constitutive nature of material objects in professional learning spaces. In particular, the research highlights the importance of material concerns in the relational and fluid dynamics of heterarchical coaching practices.