Jens is a prisoner at Långholmen prisoner. When he gets out, he decides to do one more job as a thief and then start an honest life. From one of the inmates at the prison, he has heard about a valuable diamond, sewn into one of seven black bras. When he goes to see the taylor who owns them, she tells him, that they have all been sold. Now starts a chase around the city to find the seven bras to check them out, in order to find out in which the diamond is hidden. Jens has to be very inventive, because the bras have been sold to a variety of different women and women are drawn to him like a magnet. As if this wasn't enough, two other thieves also hear about the diamond and joins the chase.