"How crazy!" A man and a woman watch episodes from Nils Poppe movies outside a cinema Maxim in Stockholm. Poppe represents, among other things, a poor composer who vainly tries to get a tune adopted by a publisher. The failure makes him depressed, but he is living it up by meeting a good friend Calle, who invites him home. Poppe stays for a few days as a male housewife. Calle has a music store and there the two friends can go crazy among all the instruments.
The wealthy Rudolf Trane helps the unsuccessful vacuum-cleaner salesman Rhuter to find a girl called Marianne. Trane, Rhuter and Trane's manservant John pretend to be waiters when Marianne's family is having a large dinner.
Jan-Erik, jeune lycéen, est brimé par Caligula, un professeur de latin tyrannique. Il tombe amoureux de Berta, une jeune femme aux moeurs légères. Celle-ci lui confie qu'elle est harcelée par un homme, qui se révèle être Caligula.
Une assistante sociale s'infiltre chez un chef de bureau accusé de mauvais traitements sur ses domestiques. Mais son fils séduisant vient compliquer ses plans.