'The Coldest War': With the polar ice caps shrinking due to global warming, new trade routes are being exposed, along with billions of dollars' worth of natural-resource reserves. The five nations bordering the Arctic are readying themselves to fight for it. The problem is that there's one non-NATO country that already considers itself rightful owner of the region: Russia. With Vladimir Putin's recent military annexation of Crimea, there's a definite possibility its aggressions will boil over, returning the international community to precarious Cold War footing. We will head north to witness NATO forces participating in the largest polar military exercise in history. 'Heroin Warfare': Since the U.S. occupation of Afghanistan, heroin production in the region has skyrocketed, making the country the number-one producer by a large margin. Though Iran, Afghanistan's neighbor, is an ultraconservative country, Afghan heroin flowing across the border has actually caused Iran to have the worst heroin use problem in the world. Suroosh Alvi gets a rare look inside Iran to meet the suffering heroin addicts, and see how the country is coping with the illegal drug trade.

Rockefeller, Carnegie and Morgan team up to help elect William McKinley to the U.S. presidency by paying for his 1896 campaign, to avoid a possible attack on monopolies. However, fate intervenes when McKinley is suddenly assassinated, and vice president Theodore Roosevelt assumes the presidency and promptly begins dissolving monopolies and trusts in America. Meanwhile, Morgan buys out Carnegie Steel to make Carnegie the richest man in the world, and Henry Ford designs an affordable automobile with his Model T and starts his own business, Ford Motor Company, which sets a new business model for companies to follow.

In the second episode, the directors learn their vision for the films is not always permissible by the U.S. government. Wyler is shocked by the racism he encounters against African American soldiers and refused to make a film recruiting black soldiers. Meanwhile, the films' racist depiction of the Japanese versus human depiction of the Germans causes worry for the War Department, which at that time planned to redistribute the Japanese-American population from internment camps into towns across the United States.

The five directors, John Ford, William Wyler, John Huston, Frank Capra, and George Stevens, return to Hollywood after the war but are forever haunted by what they saw. Ford goes on a drinking bender after filming the carnage at D-Day. Stevens is wholly unprepared for the horrors of Dachau and realizes he is not there to film propaganda but to capture evidence of crimes against humanity. Wyler, who lost his hearing during the war, fears his career is over. Huston chronicles soldiers suffering from postraumatic stress disorder in the film Let There Be Light, only to have it suppressed by the U.S. government.

American troops launch widespread 'search and destroy' operations; body count, not territory, becomes the measure of success in Vietnam. Charles Brown fights for survival on the bloody slopes of Hill 875 and at home, the American public begins to question U.S. military strategy.

The enemy gains ground when the massive Tet Offensive catches the Americans by surprise. At Khe Sanh and Pleiku, U.S. troops are under siege. Americans mount a counteroffensive but the shock of the assault ignites anti-war fervour at home.