Krajewski, a young bank clerk, is a romantic and dreams of perfect love. One day, he accidentally meets a beautiful girl whom he helps dry her clothes in his apartment after she falls into a puddle while getting off the tram. Enchanted by her beauty and delicacy, he falls madly in love with her, believing that he has found the love of his life. Frania, as the girl is called, disappears every evening, claiming that as a seamstress she has a lot of work and has to work at night as well. In reality, under the assumed name of Irena, she spends her nights as an escort at the Orfeum cabaret. Afraid of losing her beloved, she does not reveal the truth to him. However, the idyll does not last long.