A big musical is being staged in post-war Vienna. Hannerl Möller has always wanted to be a dancer but her father disapproves. Nonetheless she has secretly been taking lessons and now manages to get in to rehearsals. She is turned down by the producer, but she gets to see his father and says that she is his (the father's) daughter. Well, he thinks, it's possible; when were you born? So he thinks he knows who the mother is. When the leading dancer has a tantrum and quits, he persuades his son to let Hannerl take the role. Nonetheless, her real father has to sign the contract as she's under age, and he refuses to do so. So her mother comes to the theatre and introduces herself ... as the apparently long lost girlfriend of the producer's father. After several drinks, the complicated relationshipos look even more complicated.