Jean Bazard and the lawyer Alphonse Car are rivals of the beautiful Rose Legrange, but Bazard wins her love. Carrel is more successful in his shameful economic speculations together with banker Leroux, who is Roses's uncle.

Calle Lundgren is a shop assistant and spends most days as errand boy for Nisse and flirting with the ladies, especially a girl called Amanda. One day Calle read in the newspaper that he is the sole heir to a Swedish American millionaire who has just died.

Count de Faber is working on a new type of explosive, but finds out that Professor Plussman has beat him to it. After an unsuccessful attempt to acquire the formula from Plussman, he breaks into the professor's house, steals the formula, and kidnaps his daughter, Mary. He takes her to Carlsten Fortress.