The year is 1925. Mölle is the fashionable tourist destination for people of a certain class. Ladies with shingled hair, men in straw hats and white suits. At the popular guest house Summer Lust the uptight but lovesick Beda rules with an iron fist. To help her she has a lot of very good personell... and Siri. Siri works as a bartender, is obsessed with movies and not very interested in helping the guests.

As always, Sickan has come up with a new plan. This time he wants to rob the IKEA furniture store. During their nightly break-in Sickan discovers that the store is used as a secret smuggling central for sending American computers to the Soviet Union. The computers are picked up by Soviet submarines sneaking into the Swedish archipelago. Naturally, it is their arch enemy Wall-Enberg who is behind all of this.

To secure an order for 1 000 cabin cruisers from an Arab prince, two companies have to compete by racing each other by canal from Stockholm to Gothenburg. A small family owned company on the brink of bankruptcy is pitted against a much larger competitor and both resort to dirty tricks in order to reach the goal line first.

Sickan, the leader of the criminal Jönsson gang is incarcerated in a mental institution, attended by Dr M.A. Busé, who admire a handbook in crime that Sickan has been writing. Blackmailed by the nefarious banker Wall-Enberg, Dr Busé and Sickan's partners Vanheden and Dynamite-Harry execute Sickan's plan of stealing the valuable Black Diamond of the Romanovs from the National Museum.

A botched burglary leads to the arrest of the Jönsson gang’s leader, Sickan. After serving ten months in prison, he is released and unexpectedly recruited by the enigmatic banker Wall-Enberg Jr. to steal the legendary Bedford Diamonds in Switzerland. Though Sickan successfully carries out the heist, he is betrayed and nearly captured. Returning to Sweden and reuniting with his old accomplices, he sets out to take calculated revenge on the man who double-crossed him.

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.

Three friends, Robban, Alexander and Kim has just left the compulsory school, and now they consider themselves grown-up and mature, being 16 years old. During the summer holiday they also get a bit of experience of the world: Robban becomes a full-time drug addict, Alexander plays in a rock band but leaves it and Kim is desperate to get the girl of his dreams.

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?

Vanheden and Dynamite-Harry are approached by Sickan's grandmother and Sickan's younger brother Sven-Ingvar. Their evil nemesis Wall-Enberg are planning to steal billions of euros of the European Union's grants to culture. The grant of 350 million kronor, paid by an Italian bank acting as intermediary, equals 60 billion lire but through assistance of a Sicilian "businessman", this sum becomes 60 billion kronor when transferred. The money is to be transferred to a large number of bank accounts, and the account numbers are saved on a floppy disc that the Jönsson gang is trying to steal.

Vanheden and Dynamit-Harry, together with Harry's fiancée Doris, are in Mallorca while Sickan is still in Stockholm. However, Wall-Enberg talks him into doing a break-in at Las Palmas cathedral in Mallorca. Once persuaded, he can't resist the temptation and travels to Mallorca as well. However, Wall-Enberg obviously can't be trusted. Sickan is framed, caught and put in jail. While being escorted home to Sweden again, Vanheden and Harry sets up a plan to break him free. Sickan, once free, wants payback. The gang discover that an antiques dealer called Germann has something to do with the whole thing and that she's also collaborating with Wall-Enberg. The gang then decide to take a closer look at her and her antiques and they discover that there's a heist being planned against the cathedral in Palma.