For the first time there appeared Axel Strøbye as Kriminalassistent Jensen, pursuing the gang in all later movies.
A robbery in a cinema goes awry when the alcoholic brother of Benny, Dynamite-Harry, surprisingly arrives in the middle of the robbery, and Egon ends up in jail yet again, meanwhile the rest of the gang, including Harry, escapes.
Egon is released eight months later, but many things have occurred while Egon has been behind bars. Benny and Kjeld have got a permanent job at a local merchant, run by an elderly man named Quist. His daughter Ragna has fallen in love with Benny, to the dismay of her father, who would rather have had an academician. Egon must settle with Dynamite-Harry, as Benny and Kjeld are not interested in the plan Egon has worked out in the prison. The plan is about stealing 6 million kroner - money that cannot be traced. Dynamite-Harry has quit drinking totally after messing up the robbery in the cinema, and he happily helps Egon with a robbery in a merchant. However, it turns out that the merchant they try to rob is the shop where Benny and Kjeld works, and the safe is empty. Benny and Kjeld are doing overtime but are accused of the robbery and imprisoned as Egon and Harry flees before the merchant Quist appears with a rifle, before calling the police.
Later, Egon free his friends during a prisoner transport. Now with the gang reunited, they can now go on with Egon's plan. The money are placed in a safe at a warehouse in Christianshavn. The plan is to sneak in through the sewage system, and to continuing up towards the offices where the safe is, secured with light-sensitive alarms and hydraulic doors. However - a few hours before the robbery, Benny and Kjeld are visited by the merchant and Ragna. They want to clear out with their former employees because Ragna still loves Benny. Egon is yet again left on his own, and this time he can't even persuade Harry to join him, especially not if they are going to sail in a boat, which is part of the plan. He decides to complete the robbery on his own, and it goes well until he has to go down a manhole cover in a cold storage, where a guard appears. Having to think quickly, he hides in an unlocked cold room.
Meanwhile, Benny and Kjeld have realised how badly the economic situation is in the grocery store, running at a major deficit. The two gang members run away and try to find Egon. They appear in the cold storage's sewer in the exact moment the guard is on his way out. He hears the sound of the manhole cover, turns around and discover that one of the rooms is unlocked. The guards locks the room, with Egon still inside and he is now trapped in a freezingly cold storage room. However, he manages to get Benny and Kjeld's attention by knocking on the door, and they realise that he is locked inside the room, they are unaware however that the room he is trapped within is a cold room. Benny think of Dynamite-Harry, who can blow a hole in the wall on the other side of the cold room, and this time they have to dress up as men transporting beer. They "loan" an beer van and bring Harry along by forcing him to sit at the back of the van, surrounded by thousands of filled beer bottles. Egon is saved. However, the temptation is too big for Harry at the back of the van, and he is soon in cloud nine, singing Danish psalms in drunkenness.