Andrzej Kwiatkowski is a surgeon for the Polish army who successfully operates on a secret political police colonel in the barracks hospital. As a reward, he is given a week off by his grateful patient. Together with his friend, he heads to Warsaw, where he rekindles an old romance with Krystyna. As a consequence of an argument with some Russian soldier, Andrzej pretends to be a communist army colonel in order to save innocent people from Stalinist imprisonment and to get the heart of the girl he is in love with.