By day he was a devout Catholic father of six who attended early-morning Mass. For more than two decades he was also a mole, selling America's deepest secrets to the Soviet Union and later Russia in what the Department of Justice called possibly the worst intelligence disaster in U.S. history. This episode unpacks the strange psychology and tradecraft of FBI counterintelligence agent Robert Hanssen, a man uniquely trained to understand systems and exploit their blind spots.

We trace his betrayals, from exposing double agents who were executed, to handing the KGB the FBI's own mole-hunting playbook, to the staggering institutional failures that let him operate undetected. We follow the disturbing double life behind his pious facade, the seven-million-dollar purchase of a Russian file, the obscure Patton quote that cracked the case, and the y ...