In the US, the film was nominated at the 1939 Academy Awards for "Best Original Score" and made a profit of $38,000. Modern Screen gave the film 4 out of 4 stars, stating that the film was "a powerful message against war and hatred", and that it maintained its level of suspense throughout the course of the picture. They praised the acting, particularly that of Anna Neagle in the title role, as well as May Robson, Edna May Oliver, and ZaSu Pitts in their roles of women who aid the fleeing soldiers. The performance of Rex Downing was called "notable", and that of Lionel Royce was described as "stand-out". Also commended were George Sanders, Mary Howard, Sophie Stewart and H.B. Warner. The magazine was especially enthusiastic of Herbert Wilcox's direction, in that he managed to make every part credible, and even the roles of the "heavies" managed to be shown with compassion and understanding.
English nurse Edith Cavell is matron in a small private hospital in German-occupied Brussels during WWI. When the son of a recently deceased patient escapes from a German prisoner-of-war camp, Cavell aids him to reach Holland and safety. This leads to Cavell, a local noblewoman, the grandmother of the escaped prisoner-of-war, and others to form an organization to help Belgian, French, English and other soldiers escape as well. Eventually the Germans become aware of what's happening and take action.