In 1963, former British agent Kim Philby fled Beirut for Moscow, just avoiding a CIA hit team, and closed the door on the Soviet Union's most successful penetration of Western intelligence. His exploits as a Soviet mole - he served as MI6's chief link with the CIA in Washington, and was the lynchpin of the notorious Cambridge spy ring - have inspired spy novelists from John le Carre to Len Deighton. Russian journalist Genrikh Borovik, drawing on information culled from KGB files and from Philby himself, sets out to answer lingering questions about the Soviet master-spy. The book's coverage ranges from Philby's recruitment at Cambridge to his involvement in a plot to assassinate Franco, and from the KGB's doubts about his loyalty to details of espionage trade-craft.