Poland, immediately after WWII: a highly stressed French Red Cross unit isworking MASH-style to treat and evacuate numerous wounded French soldiers when a desperate Polish nun asks for emergency help. By rule the corpsmen can treat only French military, but by luck and by example the nun moves a young French nurse to break that rule. At the convent she finds that the emergency is that a nun is about to give birth, and with no more help than her sisters' whispered prayers. The subsequent revelations are all convincing and all horrible, especially because the nuns have had to survive--just barely--both the German invaders and their Russian liberators. A.k.a. rapists. This riveting and beautifully filmed story is said to be based on fact. That always makes me want to know more than the 'based on' part. 'Facts are stubborn things,' as John Adams said, to which I add that filmmakers are malleable. They have to make the facts into a story. In this case I felt the wind-up of the story was a high-fructose invention—pat, glib, convenient. Excellent nevertheless.