[1] Following the Olsen Gang's only successful robbery in the previous film, they are seemingly living the perfect life in the basking sun on Mallorca,[a] but they are not happy.

Kjeld is homesick, Yvonne has turned into an alcoholic, and money-wasting Benny is in conflict with Egon who has the red suitcase containing their money always chained to his wrist.

The gang steal a small shunting locomotive, hijack the wagon and transfer the gold onto a battered medium truck,[2] which collapses under the load.

The gang has to abandon the gold to escape the police, split up in disagreement, but regroup with a new plan after Benny and Kjeld rescue Egon from "disappearing and staying lost".

In addition the police have arranged a summer outing via rail and by chance, Bøffen spots the gang towing the wagon along the Copenhagen harbour railway and a car/train chase along Amagerbanen ensures.