This first section is intended to set the scene. The aim is to open up debates that transgress practice and theory, which in turn are covered further on in this volume. It is also intended in a way to underline why we decided to ask so many people to contribute to this handbook. It is our view that public protection, risk and dangerousness have assumed a position of very considerable influence within the wider criminal justice process. This is obvious in the more overt developments in legislation such as the introduction of indeterminate sentences for public protection (IPP), but we would argue that its influence is far more widespread. For example, the creation of multiagency public protection arrangements (MAPPA) has not only led to closer working relationships between previously quite distinct agencies (police and probation), but has also drawn in a much wider family of agencies as those having a ‘duty to cooperate’. From employment services, to victims’ groups and housing authorities, the public protection network has spread its tentacles far and wide. In so doing there have inevitably been signs of cultural transference between them, none more so than between police and probation. We would argue that the public protection ethos is a powerful one, fully supported by governments and, of course, a constant source of interest for the media. It is a difficult agenda to resist and indeed has spread its influence to other areas of criminal justice practice. The probation service, for example, has significantly shifted its focus over the past two decades, and while this is not entirely due to the growth in public protection it has probably facilitated and accelerated that change. The chapters in this first section are therefore intended to explore the significance of the public protection agenda including a historical overview, a theoretical analysis and an exploration of its politics.