In 1963, at the height of the Cold War, a well-educated Englishman called Kim Philby boarded a Russian freighter in Beirut and defected to Moscow under the nose of British Intelligence. For 30 years he had been spying for the Soviet Union while holding senior jobs in the intelligence agency, MI6. Was his escape from justice an embarrassing mistake or part of a plan worked out with the Soviets?

In 1963, at the height of the Cold War, a well-educated Englishman called Kim Philby boarded a Russian freighter in Beirut and defected to Moscow under the nose of British Intelligence. For 30 years he had been spying for the Soviet Union while holding senior jobs in the intelligence agency, MI6. Was his escape from justice an embarrassing mistake or part of a plan worked out with the Soviets?