Ben Macintyre tells the extraordinary true story of Oleg Gordievsky, a KGB officer who secretly worked for British intelligence for over a decade. Gordievsky, motivated by genuine belief in Western democracy rather than money, provided MI6 with crucial intelligence during the Cold War's most dangerous years. Macintyre, with access to Gordievsky himself and extensive research in intelligence archives, reconstructs both the spy's work and his dramatic escape from Moscow in 1985. Gordievsky was betrayed by Aldrich Ames, a CIA officer selling secrets to the Soviets, and had to flee through Finland in a car trunk. The book is a masterclass in spy narrative, combining the tension of a thriller with historical depth about Cold War intelligence operations. Macintyre examines how Gordievsky's information helped Western leaders understand Soviet thinking, particularly during the 1983 war scare when Moscow genuinely believed a NATO attack was imminent. The personal story is equally compelling: a man who lived a double life for years, loving his country while believing its system was evil. This is one of the great true spy stories, told by a writer who has made the genre his specialty.