The Olsen Gang realizes that cash is obsolete with the current inflation rate, and plans a coup for property and bonds. They make a fake company and tries to buy Oslo's biggest shopping mall, Steen and Strøm.

Nine oldtimers come upon a young woman stuck in a swamp.

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.