Book - Spycatcher
Spycatcher: the candid autobiography of a senior intelligence officer.
From the end of WWII until 1965 when Roger Hollis left as head of MI-5, British counterintelligence was almost completely compromised. The Soviets outmaneuvered them continuously with a flood of diplomatic and illegal agents. This was a constant source of embarrassment as people like Kim Philby, Burgess and McLean defected to the USSR. The agents defecting in the opposite direction were frequently clever disinformants sent as ploys creating a "wilderness of mirrors." As former assistant director of MI5 the author was directly responsible for investigating the infiltration and gives a blow by blow account of how morale suffered as one by one potential moles were grilled and either cleared or ousted. Many interesting and authoritative asides keep interest high throughout the work.