Ever since he was enthralled and appalled by the murders of Bible John, a psychopath who haunted Glasgow dance halls and killed three women, disappearing without a trace, Andrew O'Hagan has wanted an answer to this question: how can people disappear off the face of the earth? How could Frederick West's victims go unnoticed? Every year in Britain some 2000 people go missing. In this book, O'Hagan looks at real cases known to him personally and concludes with an account of the missing persons killed by the Wests of Gloucester.