This chapter lays the groundwork for the book by providing a broad overview of its central themes, concepts, and goals. It begins with a foundational discussion of what is currently known about missing persons, drawing on existing research, available data, and key trends from both international and Canadian perspectives. The chapter connects these realities to dominant views in the literature and public opinion, demonstrating how sensationalist narratives, reinforced by true crime entertainment and media portrayals, have shaped broad understandings of disappearance. From there, it turns to what is less understood, emphasizing the significant gaps in research and knowledge that leave the nuances and complexities of this phenomenon underexplored. The chapter introduces the datasets underpinning this book’s effort to address these limitations and concludes with a roadmap that previews the central arguments and insights developed in each subsequent chapter.