Barbara Richter actually studies medicine – but it is wartime, and the universities are closed. So, she works as a conductor for the Berlin transportation agency. Like many other women, Barbara also supports the German soldiers; she sends of them a small package. She sends Friedrich Schröder, one of the men in the field, cigarettes every week – without suspecting that he is happily married.
One day, Friedrich comes with two comrades (Emil and Fritz, who is single) to Berlin. Friedrich sends Fritz to the good-natured and hoping-for-love and patiently waiting Barbara to explain that he is married. But because of a misunderstanding, Barbara thinks Fritz is Friedrich and is wholly convinced that the attractive chap sitting across from her is married. In her rage, she leaves him before he has the chance to explain the situation to her – and in fact, that he fell in love with Barbara at first sight. As he tells Friedrich of the hapless attempt, his wife offers to intervene: she seeks Barbara out and makes sure that Fritz and Barbara make amends and can happily come together.