Lotte Körner and Luise Palfy are amazed when they meet one day in a boarding house. They do not know each other, but are amazingly alike. Of course, they must be twins! But why were they separated? They want to investigate and decide to change roles. Lotte goes to her father as Luise, Luise as Lotte to her mother. That sounds more simple than it really is: both have led very different lives. And then everything becomes clear.