Christmas is just around the corner, and in Benny and Kjeld's class, a new boy, Egon, starts. The three quickly become friends. Egon, who lives in an orphanage, says that there will be neither Christmas presents nor a party for the children at the orphanage, as the Christmas fund's greedy board has spent all the money. Egon is sure that there is cheating in the game - and of course he has a plan! The three decide to solve the mystery immediately, but a lot of problems arise: Børgefar is kidnapped, Yvonne has to choose between Bøffen and Kjeld, the police assistants Holm and Jensen mess with it as usual, and is it at all possible to open the Franz Jäger safe? The Olsen gang does everything to solve the mystery before Christmas Eve, so that gifts can be bought for everyone ... But will it succeed?