Mexico City was the Casablanca of the Cold War-a hotbed of spies, revolutionaries, and assassins. The CIA's station there was the front line of the United States' fight against international communism, as important for Latin America as Berlin was for Europe. And its undisputed spymaster was Winston Mackinley Scott. Chief of the Mexico City station from 1956 to 1969, Win Scott occupied a key position in the founding generation of the Central Intelligence...