Sickan has a new plan. This time, the gang are going to steal a small computer micro chip which contains a top secret plan of what the government intends to do with Sweden in the future. But, Wall-Enberg is also planning to steal the chip. The payment will be 55 million Swedish crowns in gold and diamonds to whoever can deliver the chip to the foreign investors. Who will grab hold of the chip, the Jönsson gang or Wall-Enberg?
Sickan, Vanheden and Rocky try to rob the Berns nightclub one night, but Vanheden has made the mistake to invite his constantly drunk cousin, the old dynamiter Dynamite-Harry and he ruins the plan. Sickan is arrested, and has to spend 10 months in a small, locked room. When he is released, he has a new plan, but Rocky and Vanheden have decided to go straight. Together with Dynamite-Harry, Sickan plans to rob a cold store, managed by their arch-enemy, Wall-Enberg.
The movie begins with the Jönsson gang making a minor burglary. It goes wrong and the gang leader, Sickan, gets caught. After he has spent 10 months in jail, Vanheden and Rocky come to welcome him when he's released. But he doesn't take notice of them, and he's picked up by the mysterious banker Wall-Enberg Jr. instead. He wants Sickan to perform a burglary in Switzerland, in order to retrieve the famous Bedford Diamonds. Sickan does this but is fooled by Wall-Enberg and nearly gets caught. When he returns to Sweden and re-unites with his old gang members, he's set on revenge, both physically and psychologically...
