This book offers a rigorous and accessible examination of missing persons that moves beyond the dominant true crime focus on serial killers, cold cases, and unexplained disappearances. Drawing on years of fieldwork, more than 220 interviews and surveys with first responders, and analysis of over 20,000 missing persons reports, it reveals missingness as a continuum shaped by everyday life events, structural vulnerabilities, and institutional responses, as well as rare cases of serious harm. The book examines who goes missing and why, how media and true crime shape public understanding, and how police, search and rescue volunteers, families, and communities work to locate the missing. It also looks forward, asking what prevention might look like if missing persons were treated as a sustained social priority rather than episodic mystery. Bridging research, practice, and public engagement, this book makes a distinctive contribution by shifting the conversation from fascination to responsibility, and from reactive searching to systemic understanding, prevention, and care.