Despite its extensive political, economic and social ramifications, the process of energy sector transformation in the post-socialist states of Eastern and Central Europe (ECE) and the Former Soviet Union (FSU) has received very little theoretical attention to date. In this paper, I draw attention to the multiple ways in which the energy reform experience of the past two decades has undermined established understandings of scale, reform trajectories and national boundaries in this part of the world. With the aid of concepts developed in Science and Technology Studies (STS) and Actor Network Theory (ANT), I discuss the ability of energy relations and interdependencies to create material and political ‘topologies’ and ‘entanglements’ of power in post-socialism. This exploration is grounded in a discussion of the tensions between the legacies and path-dependencies inherited from the centrally planned economy, on the one hand, and the neoliberal project for energy sector reconfiguration that became the dominant reform paradigm in the early 1990s, on the other.