The scam artist Jens Nielsen is in prison. In exchange for a cigarette, he is told by fellow prisoner, Sture Kaxe, that he has a precious jewel worth SEK 100,000 hidden away.
Librarian Roger Fleuriot is in love with princess Saint Labiche but doesn't dare admit it because of their different classes. The princess feels the same way and invents a twin sister that works in a shoe shop that she pretends to be in order to seduce him.
