The Olsen Gang in a Fix

Egon is released from prison after his failed bank robbery attempt and is rehabilitated by Bodil Hansen, an attractive social welfare officer. She helps him find a steady job at a toy factory, and he genuinely tries to prove he can live as a law-abiding citizen. This change of heart is short-lived once the gang is falsely accused of the bank vault robbery.

The film opens with Egon's failed robbery attempt, establishing his criminal pattern before his attempted reformation.

The robbery was carried out by mafia boss Serafimo 'Spats' Motzarella and his team. They planted the stolen loot, allegedly the Danish crown jewels, in a cello case to smuggle it out of the country. The gang happened to be working as cleaners at the bank during the heist, which is why police mistakenly blamed them.

The gang was working as cleaners at the Danish National Bank when Motzarella's mob robbed the vault. Since they were on-site and had criminal histories, police immediately assumed they were responsible. The real perpetrators escaped while the gang was left holding the blame, forcing them to clear their names.

Motzarella's plan was to secretly sell the Danish crown jewels to relieve the Danish economy. The jewels on public display at Rosenborg Castle were actually copies, while the originals were stolen from the vault and hidden in a cello case for illegal export. The gang got caught in the middle of this larger criminal operation.

After the gang hijacked the cello case from the airport, Motzarella's mob tracked them to their Copenhagen hideout, a bar. During the confrontation, the mob opened fire and the bar was destroyed as the cello case was repossessed. The gang survived and later used disguises to reclaim the case.

The gang needed to open the cello case to prove they had the real crown jewels and clear their names. Since the case was securely locked, they recruited Dynamite Harry, Benny's heavy-drinking brother who was an explosives expert, to blow it open at a remote gravel pit.

Harry's attempt to blow open the cello case backfired catastrophically. Instead of opening the case, the explosion took out the German task force that Motzarella had brought along. The cello case remained unopened, leaving the gang frustrated and the jewel mystery unresolved.

Motzarella arrives in a helicopter with a German unit to finalize the illegal sale of the crown jewels. He arranges to hand over the cello case in exchange for payment, planning to complete the secret transaction before anyone could stop him.

Bodil tracks Motzarella throughout the film, partly to test her rehabilitation methods and partly to uncover the truth about the bank plot. After Motzarella arranges the legal sale of the jewels, Bodil follows him back to the States, effectively ending her involvement with Egon.

While Egon clears his name of the original bank robbery, he is arrested for a string of petty crimes he committed during the jewel hunt, hijacking, disguise scams, and other offenses. Detective Mortensen catches up with him at a bar and arrests him for these lesser charges, sending Egon back to jail.

The film begins and ends with Egon in prison, creating a circular narrative structure.

When Benny and Kjeld return home, they find that Yvonne, with Bodil's help, has managed to restore their fortunes and possessions. This provides a small victory for the gang, even as Egon faces arrest again.