After 17 years, Egon gets placed at the
Institute for Theoretical Crime, which is a
psychiatric institution for incurably criminal persons. He had left the institution for the first time to participate in a TV talk show. Benny, who
worked in black for a
taxi company, and Kjeld, who sits in a
wheelchair and lives in a nursing home after Yvonne's death in 1987, both saw the broadcast. They both decide to immediately visit the TV studio to seek out, once again, Egon, whom they have not seen for 17 years. While Egon desperately seeks a toilet after participating in the talk show, he goes outside the studio, where he meets Benny. Together, they decide to visit Kjeld at the nursing home. Kjeld met a lady, Ruth, with whom he wanted to buy an
apartment for both of them in Málaga. Egon has a new plan to lead the Olsen gang to the necessary capital. During his long time in psychiatry, Egon has devised countless plans, all of which have been confiscated by the superintendent and are now in his
safe. The Olsen gang opens the safe to realize Egon's most significant plan: rob the English crown jewels. However, not only Kjeld and Benny could recognize Egon on television, but also department head Hallandsen from
the Ministry of Justice. This causes the Olsen gang a problem, namely that in Denmark, there is a suitcase containing the strictly confidential Wandenberg documents. If these become public knowledge, the world will collapse, as these documents contain precise descriptions of all significant scandals from the past decades. A first attempt by Hallandsen, with the help of two of the ministry's office officers, failed to steal the documents from
the Ministry of Foreign Affairs' archive, where they are kept. Because of the broadcast, he has been reminded of Egon Olsen, which makes the problem bigger. He instructs expedition secretary Holm-Hansen to find Egon. Holm-Hansen consults detective assistant Jensen, who should have
retired long ago but had to wait 17 years due to a computer error. Jensen advises Holm-Hansen to check the only Franz Jäger safe from 1944 left in Denmark, which Egon will sooner or later break open. This cabinet is located in the
Department of Theoretical Crime. Meanwhile, at the institute, Egon plans to steal his plans from the safe. On their way out, they are suddenly accosted by the headmaster, who naturally wants to lock Egon up again. At the last moment, Holm-Hansen intervenes and brings Egon; after that, Kjeld and Benny leave the institute unnoticed. Egon is brought to Hallandsen, who gives him the task of stealing the Wandenberg documents—of course, for a measured reward. After the two office officers have helped Hallandsen, Egon steals the documents within a few minutes. After Hallandsen has obtained the documents, Egon demands the promised reward but is instead locked up in a dungeon in the Ministry of Justice, where he is again attacked by Bøffen and his assistant Alf. However, Kjeld and Benny manage to free Egon at the last moment. Hallandsen wants the suitcase with the Wandenberg documents destroyed at the state-of-the-art state destruction facility, which Egon wants to prevent and bring the suitcase into his possession to blackmail Hallandsen. Together with Benny and Kjeld, he can—with the help of a boat hook, a bottle of
washing-up liquid, and numerous other remedies—take back the suitcase with the Wandenberg documents. Hallandsen is deeply shocked as he drives away. Bøffen and Alf attack Egon again. When the Olsen gang drives to the construction site of the
Øresund connection, where the suitcase must be delivered, Ruth suddenly gets into the car instead of Kjeld. She justifies this by saying that Kjeld is not feeling well and that she is, therefore, coming in his place. Reluctantly, Egon allows her presence. When they arrive at the construction site, Egon, Benny, and Ruth are attacked again by Bøffen and Alf and lowered into a construction cave. There, they—together with the Wandenberg documents and Egon's plans—must be removed from the road. As a result of Egon's intervention, they can be freed. At the same time, they meet an old acquaintance in Denmark - Kjeld's son Børge, who lives abroad as an international
company manager. He learns from Kjeld what has happened and then starts looking for Egon, Benny, and Ruth. He meets the happily assembled Olsen gang when he arrives at the construction site. While Benny says goodbye, Egon demands his reward from Holm-Hansen. In the next moment, Egon watches helplessly as Ruth and Alf throw the suitcases with Egon's plans and the Wandenberg documents onto a construction machine, after which they disappear without a trace. Hallandsen wants to flee to
Jutland, and Holm-Hansen gets appointed as his successor, whose first action is to retire detective assistant Jensen. At the film's end, Egon, Benny, Kjeld, Ruth, and Alf travel to Børge's villa in
Portugal to live the rest of their lives in peace and quiet. Egon still plans to carry out the remaining plan: steal the crown jewels. ==Cast==