Jungle warfare was perfected by the North Vietnamese. From their hidden tunnel cities, the Viet Cong launched operations that were terrifying in their ingenuity, savagery, and persistence. The 10-day battle for the place that came to be known as Hamburger Hill was perhaps the classic conflict of the Vietnam War. Piecing together newly disclosed stories from both sides, we learn how American commanders made the mistake of fighting this battle as they had fought WWII. The North Vietnamese, employing a very different set of strategies, built a massive warren of tunnels and then faded into Laos when the battle turned against them.