With Sanna as the driving force, the Storm family decides to try to persuade their warring neighbors to take part in the Christmas fight. With bribes and flattery, it turns out that you can get far.
After signing up for the Christmas match, Sanna gathers for a big meeting at Lugna gården. Now the neighbors will try to cooperate, which is not the easiest thing
Someone has ruined Lugna gården's Christmas decorations and it is clear that Järnkroken has a Christmas saboteur. One of the neighbors is a suspect. The children make plans to put the villain there while the adults
Lugna gården is looking for spruce to decorate the yard, but the spruce (n) sämjan turns out to be like that once again. Will takes help from dad Trond to dig a pit to catch the werewolf she suspects running loose.
In Julkampen's second sub-competition, the gingerbread house construction, Lugna gården's big ideas suddenly turn out to be very small. The reconnaissance of the shady neighbor Eskil is beginning to yield results.
At the same time as Lugna gården finally gets a little tailwind in Julkampen, the children end up in trouble down by Stationshuset. But what are Lussan's plans really?
Eskil becomes increasingly suspicious in the children's eyes and they decide to embark on a reconnaissance mission that must take place during the Lucia train.
Time to decorate the Christmas tree and Lugna gården tries to agree on what it should look like. At the same time, Trond has decided that the children will be homeschooled, which does not fit the children's plans for the day at all.
Calm farm is in crisis as one of their own is suspected. They go to the People's House to get redress. Once there, Lussan gets the Iron Hook residents on his side.
Eskil comes with evidence that gives the children new clues. In search of the saboteur, an elf leads them all the way to a treasure hideout. The masked villain must finally get caught.
The Christmas saboteur is fixed, but when the whole Järnkroken is to be redecorated, Maja and Leo make new discoveries that change everything. Especially for some of Järnkroken's residents.
Day before day before day and Lugna gården grinds on details to floor the Christmas jury. Grandma Gudrun shows up and helps the children tie the last threads in the mystery surrounding the Christmas saboteur.
Leo's plan to get everyone together in Järnkroken is grand and daring and when the winner of this year's Christmas match is to be presented, the excitement is total.