In 2005 a crew tunneled 260 feet under the city of Fortaleza and walked out of a central bank vault with 160 million reais, roughly three tons of physical cash. It was the perfect heist, until the thieves discovered that surviving the wealth was far deadlier than stealing it.

This episode breaks down the audacious engineering of the Banco Central burglary and the brutal underworld economics that followed. It's a story about why a mountain of untraceable cash is a toxic, dangerous asset, and how the people who pulled it off became prey themselves.

• The fake landscaping front business that camouflaged the removal of roughly 30 tons of excavated soil in broad daylight
• The air-conditioned, lit, reinforced tunnel and the diamond drills used to breach a reinforced vault floor
• Why the crew targeted used, unmarked 50-real  ...