The author of this book is a former NCIS Special Agent and Analyst, and was involved in the collection and production of history, organizational facts, and lore. This book is a sampling of cases and operations conducted by the real NCIS; the organization that serves as the basis of the long-running TV hit show. The book will be of particular interest to anyone who enjoys the TV show NCIS, to anyone who has served in the US Navy or the US Marine Corps, and to anyone having an interest in the military and / or law enforcement. The author takes the reader through the history of the Naval Criminal Investigative Service (NCIS), beginning with their early days as part of the Office of Naval Intelligence, and growing into the organization it has become today. There are numerous case summaries of actual investigations and operations, covering the fields of felony crime and foreign counterintelligence. NCIS has broadened its mission through the years to support naval operations in war zones, naval warships at sea, and to counter cyber, espionage, piracy, and terrorism threats. This book takes the reader on an informative journey through this mission, and it does so by using first-hand accounts or documented case summaries. This book is written with clarity, and for the purpose of encompassing the history and camaraderie of NCIS spanning over 100 years.