This chapter introduces the problem that this book addresses: how do societies come to be constructed in such a way that residents cannot drink the water that is supplied to them? The example of the supply of water to Shanghai is taken as a case through which to examine this question. Shanghai, it is argued, is an assemblage of interacting actors. This book examines the properties and characteristics of four principal actors: the hydro-geological conditions and rivers that provide water; the people, corporations and institutions within Shanghai who use and pollute the water; the institutions of central and other governments that regulate the use of the rivers and the discharges into them; and the infrastructures that governments and corporations have built to manage the river. The chapter concludes by outlining the organisation of the chapters through which the book addresses the question.