In 1954, CIA and MI6 engineers pushed a 450-meter tunnel under the most militarized border on Earth to tap three Soviet telephone cables carrying the Red Army's secrets. The tunnel worked, capturing 67,000 hours of audio over nearly a year. The staggering twist: a Soviet mole named George Blake had betrayed the plan before the first shovel hit the ground, and the KGB let the West build it anyway to protect him.

This episode unpacks Operation Gold as the ultimate Cold War paradox, exploring the desperation for intelligence after the Soviet hydrogen bomb, the engineering ordeal of moving 3,000 tons of dirt and wading through a buried cesspool, and the brilliant calculation behind the KGB's silence. We follow the theatrical 1956 "discovery," the awkward timing during Khrushchev's UK visit, and the long debate over who really won.

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