It's 1944 and Poland is under brutal German occupation. In London, Jan Nowak-Jezioranski is a Free Poland soldier acting as a courier between the Polish government in London and the resistance in his home country. The Allies have decided that Poland shall be under Soviet control after the war. Jan is to deliver a message to stop the impending uprising.
In this movie, Jan is a horrible spy/courier. He is too impulsive and so pushy as to stand out in a crowd. The girl is too obvious at the moment of the party. Her reveal loses some of the shock. There is a difficulty with the story in that the history is well known. The question is how to generate any tension from his mission when the end is already written. I almost want the execution scene. It does settle on an internal conflict within Jan but it's not set up at all. Despite all that, there are moments of great emotional drama like the old farmer lady. There are some tension with some of the pursuit like the train. Those little moments elevate this war drama despite its various issues.