At the time of this book going to print, the Covid-19 pandemic has triggered a global crisis like no other. In particular, it has made all too clear the fragility of global value chains, one of the foundations upon which foreign direct investment (FDI) is built. Indeed, UNCTAD has estimated that FDI flows declined by 49% in 2020, hence it is more important than ever that host economies look after their established foreign investors. And so now, more than ever, is the time for Aftercare, the function that focuses on growing, retaining, expanding and linking foreign investment, to move to centre-stage. This book invites practitioners, policy makers and the whole FDI industry to embrace Aftercare, to give it its rightful place in the economic development toolkit and to work together to expand its knowledge base. This chapter introduces the core principles that underpin post-investment, the research methods we used, what this book covers, how to use this book and how Aftercare can contribute to building sustainable and inclusive societies.