In 1836, the Bank of England received anonymous letters claiming their "impenetrable" gold vault was compromised. Skeptical directors agreed to a midnight meeting inside the vault, only to watch a man pop up through the floorboards to greet them.
• The Breach: A sewer worker discovered a forgotten drain on Threadneedle Street that ran directly under the vault.
• The Vulnerability: Only a single loose stone separated the London sewers from the nation's gold.
• The Reward: Though he stole nothing, the Bank rewarded his honesty with £800- roughly £80,000 today.
