He’s been called “the most damaging British traitor of the Cold War,” “the spy who got away.” His name is George Blake, and he’s 93 years old. Today he’s a doddering, harmless-looking old coot living in Russia. Half a century ago, however, he was a very slick character indeed who, to quote an interviewee in a recent BBC documentary, was “responsible for getting people killed.”

The documentary, entitled George Blake: Masterspy of Moscow, aired on the BBC last year. Made by filmmaker George Carey (not to be confused with the former Archbishop of Canterbury of the same name), it recounted Blake’s exceedingly curious and colorful early years: born in Rotterdam in 1922 with the last name of Behar, he grew up in the odd position of being unable to communicate with his own father, an Egyptian Jew, hard-working businessman, and British subject who, though he lived in the same house as his son, spoke English and French but not Dutch, which at the time was the only language the son spoke.

After the father died, in 1936, leaving the family in financial difficulties, it somehow came to the attention of his widow and children that he had a rich sister in Cairo who lived in a palace, no less. George, then in his early teens, came into contact with his aunt and presently relocated to Cairo, where he moved into the palace, enrolled at the English School, and learned both French and English. (One presumes he must have picked up at least some Arabic, although there is no mention of this in the documentary.)

He was visiting his family in The Hague when World War II broke out, and a year later was in Rotterdam for the Nazi air raids of May 14, 1940. Returning to The Hague to discover that his mother and sisters had fled for Britain, George joined the Dutch Resistance, found his way (a rather spectacular feat) to the U.K. via Spain in 1942, and, after arriving in London, managed to parlay his remarkable personal story into a job with the Secret Intelligence Service (SIS), better known as MI6, which sent him to Cambridge to learn Russian.

It was there, in a class taught by a professor who inspired in him “a romantic admiration for everything Russian,” that Blake, according to the documentary,  first began to sympathize with Communism. (Blake himself has testified otherwise: when he’d first moved to Cairo, he’d met one of his cousins, Henri Courel, a Communist whose views, he said years later, “had a great influence on me.”)

Sent to Seoul by MI6 in 1948, Blake was apprehended by the Communists after the Korean War broke out. They could’ve executed him, but instead he allowed himself to be turned – to accept the role of a double agent, spying on the British for the North Koreans’ Soviet masters. By this point, he was not a tough sell: “I felt I was on the wrong side…that it would be better for humanity if the Communist system prevailed, that it would put an end to war.” Indeed, Blake, who had once aspired to be a pastor, would later say that he “viewed Communism as an attempt to create the kingdom of God in this world.”

What happened next? Tune in tomorrow.