'Heroin Crisis' - America is facing the worst drug epidemic this country has ever seen: more people are dying from overdoses than from car accidents-and at the center of it is an explosion in the use of heroin. Thomas Morton traces the causes and impacts of the crisis, from the poppy farms of Mexico to the hills of West Virginia, and investigates how users, first responders, and government officials are responding to the new reality of American drug use. 'New Age of Nukes' - Twenty-five years after the end of the Cold War, America's vast nuclear arsenal is beginning to show its age, and the government has embarked on the largest nuclear modernization effort in our history, costing American taxpayers as much as $1 trillion. Kaj Larsen goes aboard a ballistic missile submarine and visits the facilities on the front line of our nuclear weapons program to see why the military wants to upgrade the nukes we have-and why that might be a dangerous idea.