In the classic spy novel, the secret agent is slippery and devious. We’re hoodwinked by the brilliance of the enemy. That was the way many CIA insiders explained away Florentino Aspillaga’s revelations: Castro is a genius. The agents were brilliant actors. In truth, however, the most dangerous spies are rarely diabolical. Aldrich Ames, maybe the most damaging traitor in American history, had mediocre performance reviews, a drinking problem, and didn’t even try to hide all the money he was getting from the Soviet Union for his spying.