Initially a journalist, Philby became a high-ranking member of British intelligence and is believed to have provided the USSR with classified information that caused the deaths of scores of American and British agents. Always in danger of having his cover blown by Soviet defectors, Philby himself defected to the USSR in 1963, after he was exposed as a member of the Cambridge Five spy ring. Philby died in Moscow in 1988. What killed him? Discuss
Source: The Free Dictionary