The transformation of cities depends critically upon the reconfiguration of the networked infrastructures that underpin them, which, in turn, are constantly being reshaped by a range of competing concerns: economic, technological, ecological and social. Exploration of the role of production and consumption interests in the dynamics of urban change is not new and our previous work has aimed at contributing to an understanding of these processes (Guy et al, 2001). What we have tried to introduce to the debate through this book is a critical examination of the role of intermediaries, positioned between production and consumption, across network transitions, and in different urban and regional settings. In doing so, we have explored a wide variety of different socio-technical contexts – ranging from energy, waste, flooding, water, transport, specific technologies, smart meters, labelling and water saving to wastewater treatment – examined through a wide range of different sectoral contexts – public, private, voluntary and various partnerships – and explored through different professional interests, including, for instance, architects, public servants and consultants. What emerges is a complex and shifting patchwork of socio-technical relations with no simple organizational logic.