The year is 1940. As England braces for invasion and the German army overruns Europe, two American sisters in Paris risk their lives to save a downed British airman from Nazi arrest. Linda Rossiter and Eleanor Masson soon realize the price they may pay when they read this ominous public notice: ""All persons harbouring English soldiers must deliver same to the nearest Kommandantur not later than 20 October 1940. Those persons who continue to harbour Englishmen after this date without having notified the authorities will be shot."" On Christmas Eve, the Gestapo sets a trap, and death is only a step behind the two American women.