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.
Jean Bazard (Carl Barcklind) and the lawyer Alphonse Carrel (Arvid Hammarlund) are rivals of the beautiful Rose Legrange (Maja Cassel), but Bazard wins her love. Carrel is more successful in his shameful economic speculations together with banker Leroux (Manne Göthson), who is Roses's uncle.