This chapter provides an introduction and a general outline of the book. It starts by summarizing what predictive policing is all about and why it is important to study how the police produce and act upon criminal futures with the help of algorithmic software tools. The chapter then provides a detailed overview of how we empirically addressed this task. It introduces the police departments that we studied, their embeddedness in federal political structures in Germany and Switzerland, and the crime prediction tools that they used during our research. Particularly, it details how the most prevalent software application, PRECOBS, operationalizes rational choice assumptions and near-repeat victimization theory in order to estimate the risk of residential burglary in specific areas. Eventually, the chapter briefly outlines why predictive policing must not be mistaken for a technological tool that could be analytically isolated, but must be understood as part of a larger sociotechnical system that involves various specialized parts of police work. It concludes with a brief summary of each of the following chapters.