"The Cold War: a time when microdots and wiretaps were the height of espionage technology, when weapons of mass destruction threatened the end of the world, and where the ability to break a code could mean the difference between stopping a war and starting one. But in this fifty-year conflict between America and Russia, the most valuable weapons were people, not spy gadgets. From suave MI6 officers to cheerful families in Moscow to traitorous KGB...