In the spring of 1972, North Vietnam launched a massive military offensive designed to deliver the coup de grace to South Vietnam and its rapidly disengaging American ally. But an over-confident Hanoi misjudged its opponents who, led by American military advisers and backed by American airpower, were able to hold off the North's onslaught in what became the biggest battle of a very long war. This is the story of of heroism against great odds.