Valde is looking forward to another Christmas at Egebjerggård, where he lives with his family, and they hold a Christmas market every year. But his joy crumbles when he finds out that his mother and grandfather have chosen to put the farm up for sale. Out in the forest, something mysterious is stirring, and it calls for Valde.

Valde tries to persuade his parents to take over the farm instead of selling it, but it doesn't go as planned. A meeting with a mysterious girl leads him on the trail of a family secret that may have something to do with the Egebjerggård forest.

Valde gets help from Anker to search for the mysterious girl out in the forbidden forest. But instead they find the ancient Mother Tree in the middle of the forest. It pulls Valde high, high up into the Mother Tree's crown, all the while a pair of yellow eyes keep an eye on him from the forest floor.

The girl from the forest shows up at school to Valde's surprise. At home, Rita builds another elf trap to try to catch Rang, but she catches something much bigger, setting her on a new Christmas mission. Deep in the forest, a dangerous fog spreads.

The mysterious mist of the Bog Queen causes problems at Egebjerggård. Anker's large-scale project 'Cool December' is challenged by Valde's retreat into the forest. At the foot of the Mother Tree, Tala tells the myth of the Guardian of the Forest and shows Valde how much more is at stake than meets the eye.

The hunt begins for the Guardian's seal, but Tala in wolf form has been seen by Hermansen on the edge of the forest, and this causes problems. To hide her, Valde comes up with a plan, and with the help of Anker, he tries to persuade his mother to let Tala live at Egebjerggård.

Valde and Tala are determined to go up to Grandpa's locked attic, which means a big day of truancy. But it requires help from both a 'pixie' and Tala's wolf senses. But is there anything in the attic besides dust and old boxes?

Valde and Tala go to the school library to find the Guardian's Book. Here they get unexpected help from the substitute teacher Ulla, who turns out to know a lot more about the magic of nature than most. But most importantly, Ulla knows who wrote the book they are looking for.

Valde and Tala must escape their elf duties at the Christmas market to find the Guardian's Book out in the forest. Here Valde meets Rang for the first time, who is not the only thing that has been waiting for them out in the forest, and soon the Mist of the Bog Woman comes crawling towards them.

Valde and Tala cunningly try to get Morten's help to decipher some cryptic old writing, and it leads them on the trail of the mysterious 'K'. At the Christmas market, Theis walks into the biggest elf trap Rita has ever built: a room with lots of mistletoe - and Solveig.

Valde hatches a plan to find out what his mother knows about the mysterious 'K', and who he might be. Tala becomes an unexpected part of project 'Cool December' when she is invited to join Celine's dance group, even though she has never danced anywhere other than alone in the woods.

Valde decides to defy Tala's warnings about how dangerous the Endless Forest is to humans and sets off. If he finds what he's looking for, they might not have to sell Egebjerggård at all. But Jens has already called Hermansen.

It's Lucia Day, and Valde's family is in full swing with preparations for the parade when Hermansen comes rolling in with a monster machine that can clear the entire forest and cut down the Mother Tree before Christmas. But while Tala is learning to walk Lucia, Valde gets an idea that could put a spoke in Hermansen's wheel.

The quiet peace of the forest is disturbed by Hermansen's demonic tree traps. Valde and Tala are really busy finding the Guardian's seal and stopping Hermansen before he can cut down the Mother Tree. With Anker's help, they trick their way into Hermansen's home, but instead of answers, they find a whole new riddle.

Valde realizes that the story of the pact testifies to a trust between humans and creatures that has now been lost. Now the trust must and must be restored. Valde therefore persuades Tala to involve Ulla in their findings and is surprised by how much she knows about the world of creatures.

Valde and Tala sneak into the forest, where Hermansen and the woodcutter are raging. In a race against time, Valde uses the Guardian's call to ask the Mother Tree for advice - the answer points them deep into the Endless Forest.

Valde breaks his promise of secrecy to Tala and tells Malou and Morten everything about the Endless Forest. Tala is hurt that Valde has broken his promise and disappears back into the forest.

Valde walks alone through the Endless Forest, but it is dangerous for humans to move around there alone. Soon the Mist of the Moss Woman comes rolling towards him.

Malou is worried about Valde and has called the police. They find out that it is Anker who has been playing Tala's father, and suspect that Anker knows something about Valde's disappearance. Meanwhile, Tala and Valde are caught in the fog of the Bog Woman, where they are slowly drawn far into the bog.

While the family searches for Valde, Valde and Tala are trapped in the Moss Woman's camp, where they must forever prepare the dank ingredients for her brew. But maybe there is a way out.

Just as Valde has figured out where he will find the oldest clue, Hermansen has put a lock on the entrance to it. But Valde and Tala get unexpected help in finding the Guardian's seal. NOTE: We recommend that the youngest watch the episode with an adult.

Things are looking bleak for Valde. The Guardian's seal has been broken, and it was the only way he could restore the Covenant before Hermansen cuts down the Mother Tree. Valde confides in Anker, who believes that the answer to all of Valde's problems must be found at Celine's Christmas party.

Hermansen offers Valde that the family can keep the farm if Hermansen is allowed to cut down the Mother Tree. But suddenly there is a roar from inside the forest, as the Moss Woman has taken control of the feller and is driving it directly towards the Mother Tree. NOTE: We recommend that the youngest children watch the episode with an adult.

The Mother Tree is saved, and the Covenant is restored. But Valde has failed to save the farm from being sold, so the family prepares for the last Christmas at Egebjerggård. Rita exchanges gifts with Rang, and Tala brings a Christmas present from the Endless Forest.