Father and mother Andersen and their four children live in a closed down farmside storehouse in the outskirts of Oslo. They enjoy life here, but the many neibours surrounding them are less enthusiastic about the family's lack of respect towards the supposed social order and decency they live by.
Egon returns from prison with the key to a big heist, a hidden Nazi-treasure. The Olsen Gang finds the location of the treasure, but problems arise when the international criminals Carina and Ricco shows up.