This work investigates the historical miscarriage of justice surrounding the robbery and murder associated with the Lyons Mail in 1796. Charles Oman, a noted historian, utilizes primary court records and contemporary accounts to reconstruct the events of April 27, 1796. The book examines the legal proceedings and the subsequent trials that led to the execution of Joseph Lesurques, a man whose innocence became a subject of intense historical debate. Oman provides a detailed analysis of the judicial failures and the evidentiary gaps that characterized this infamous French criminal case.

Historians and legal scholars frequently cite this work as a definitive account of the Lyons Mail case due to Oman's meticulous research into the original trial records. The text is recognized for its objective approach to a complex historical mystery that has long fascinated students of French legal history.