A thrice-married jazz aficionado who kept a menagerie of exotic pets, Maxwell Knight (1900-68) was almost totally unqualified for espionage, yet became perhaps the greatest spymaster in history, rumored to be the real-life inspiration for the James Bond character "M." Obsessed with combatting the rising threat of fascism in Britain during World War II, Knight demonstrated a gift for training fearless secret agents, and he pioneered the use of women in this role. Henry Hemming reveals not only Knight's story but also those of the men and women he recruited on behalf of MI5, and who were asked to infiltrate the country's most dangerous political organizations.