In late November 1950, units of the First Marine Division were moving cautiously through the frozen hills of North Korea. Temperatures were subzero, every single day. It was so cold that spit would freeze in mid-air before hitting the ground.
And little did the Marines know that out there, waiting for them in the frozen wastes, was the largest ambush in modern military history. At least 80,000 Chinese who had infiltrated into Korea from Manchuria.