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.

The turmoil of 1968 helps Nixon win the presidency. Troop strength in Vietnam peaks and the draft accelerates. Karl Marlantes endures bitter jungle fighting on Hill 484, and draftee Arthur Wiknik gets a grim introduction to combat on 'Hamburger Hill'. But shortly after winning both hills, US troops abandon them.

Troop withdrawals begin as the Americans train their ARVN allies to take over the war. Gery Benedetti patrols the hostile waters of the Mekong Delta. James Anderson leads a battalion into Cambodia after Nixon's controversial order. Don DeVore struggles to survive a fierce night attack, and Anne Purcell gets promising news about her husband.

Bob Clewell's helicopter crew comes under intense fire in one of the final operations of the war. Joe Galloway returns to Vietnam and in Washington, D.C., Barry Romo throws down his medals in protest. The last American troops return home and POW wife Anne Purcell awaits word of her husband's fate. The fall of Saigon brings the unification of Vietnam.

April 1453. Sultan Mehmed II unleashes an artillery attack on Constantinople unlike any the world has ever known. It's the largest concentration of cannons that the world had seen in one place. The monumental task of keeping the Ottomans out of Constantinople falls on the shoulders of Genoese soldier of fortune Giovanni Giustiniani. He and his men must defend 14 miles of city walls. Mehmed launches his ambitious plans to break through the walls of Constantinople, but Giustiniani's mercenaries manage to forestall the attacks.

Mehmed II sends his elite troops into the teeth of Emperor Constantine's defenses along the city's ancient stone walls. The defenders, led by Italian soldier-of-fortune Giovanni Giustiniani, repel every attack. Mehmed's men dig underground tunnels in an attempt to shatter city walls. The tides turn against the Ottomans when a naval blockade founders.