The Littlehampton Libels tells the story of a poison-pen mystery that led to a miscarriage of justice in the years following the First World War. There would be four criminal trials before the real culprit was finally punished, with the case challenging the police and the prosecuting lawyers as much any capital crime. When a leading Metropolitan Police detective was tasked with solving the case, he questioned the residents of the seaside town of Littlehampton about their neighbours' vocabularies, how often they wrote letters, what their handwriting was like, whether they swore — and how they swore, for the letters at the heart of the case were often bizarre in their abuse. The archive that the investigation produced shows in extraordinary detail how ordinary people could use the English language in inventive and surprising ways at a time when universal literacy was still a novelty. Their personal lives, too, had surprises. The detective's inquiries and the courtroom dramas laid bare their secrets and the intimate details of neighbourhood and family life. Drawing on these records, The Littlehampton Libels traces the tangles of devotion and resentment, desire and manipulation, in a working-class community. We are used to emotional complexity in books about the privileged, but history is seldom able to recover the inner lives of ordinary people in this way.