Few Cold War spy stories approach the sheer daring and treachery of George Blake's. After fighting in the Dutch resistance during World War II, Blake joined the British spy agency MI6 and was stationed in Seoul. Taken prisoner after the North Korean army overran his post in 1950, Blake later returned to England to a hero's welcome, carrying a dark secret: while in a communist prison camp in North Korea, he had secretly switched sides to the KGB after reading Karl Marx's Das Kapital.