Poland, winter of 1945. Mathilde Beaulieu (Lou de Laage) is a young intern working with a branch of the French Red Cross. They are on a mission to find, treat and repatriate French survivors of the German camps. One day, a Polish nun arrives in the hospital. In very poor French, she begs Mathilde to come to her convent. Mathilde life and beliefs change when she discovers the advanced state of pregnancy that affect several of the Sisters of the convent just outside the hospital where she performs.