William Melville was one of the most influential counter-espionage figures of the 20th century. He was perfect for the job, a velvet-gloved hardman who had run Special Branch and whose career had already taken in some of London’s great crime dramas, including the Jack the Ripper investigations, Irish Republican terrorism, and assassination attempts on Queen Victoria and Edward VII. Now, with the help of recently declassified records, family material, and records that have still not officially seen the light of day, the story of his Secret Service career—including the breaking of German spy rings prior to the outbreak of the First World War—can finally be told.