This chapter contextualizes the current volume by setting out what we mean by contact talk, and how this book’s discussion expands upon the topic in new ways. We begin by introducing the growth of studies on multilingual contact in the 21st century in the last few decades. We then establish why contemporary Indonesia makes a particularly interesting context for understanding the complexities of multilingual contact, and then present a pair of new theoretical mechanisms for studying contact talk: contact registers and scalar shifters. We show how these mechanisms, through our current discussion, enable the synthesis and consolidation of a number of existing tools for understanding multilingual contact (e.g., multimodality, social value, identity projects) within a single notion of semiotic complexity. The notion of semiotic complexity we argue provides insight on Indonesia, which is undergoing one of the most radical de-centralization projects in modern history. We conclude this chapter by briefly setting out how the chapters in this book address this project, and more specifically how institutions, communities and individuals negotiate semiotic complexities and redefine hubs, peripheries and their associated signs, linguistic or otherwise.