October 1962: The Cuban Missile Crisis brings the world to the brink of nuclear catastrophe. What we didn't know for 40 years was that four Russian diesel submarines in the Caribbean, each carrying a nuclear torpedo, were in position to blow the U.S. Navy out of the water. For the first time, we hear from senior Russian sub officers who reveal that they came within seconds of firing their weapons and starting the first nuclear war. Also interviewed, former Secretary of Defense Robert McNamara.