It’s WWI, and the fate of our world revolves around the worst of trench warfare in France and Russia. On December 7, 1914, Pope Benedict XV implores the heads of state and European royalty for a temporary hiatus of war to enable the celebration of Christmas. Every single warring country refuses the cease-fire. But on Christmas Eve, someone begins to sing a carol that carries through the frigid night air across "No Man’s Land." Another voice joins in, then another. This is the beginning of one of the strangest, most unique moments in history: when Christmas stopped a war.