This introduction presents an overview of the key concepts discussed in the subsequent chapters of the book. This book presents findings from a large qualitative study of bereavement following a family member or other close person's death as a result of substance use. Funded by the UK Economic and Social Research Council, the study was conducted by researchers based in the Centre for Death and Society (CDAS) at the University of Bath, in collaboration with the University of Stirling; the research was carried out in England and Scotland over three years, from 2012 to 2015. Although potentially devastating, substance use bereavement has hitherto received little attention in the academic literature. The book focuses on the role of services in dealing with substance-related deaths and is particularly relevant to UK policy and practice. It discusses the insights that emerged from the focus groups and the working group.