DR's big, new adventure series for the whole family, broadcast every day during Easter. In the series, Niels tracks down a missing treasure in Northwest Jutland in a forgotten German bunker from World War II. Together with his sister and his friends, he sets off into the depths to find the treasure, because if they find it, they might be able to save their school from closure. However, they are not the only ones looking for the treasure, and the adventure becomes much more dangerous than they thought...

Nanna is given responsibility for Niels and packing up their rooms while their father is in Næstved to see the family's new home. However, Niels, Charly and Tania trick Nanna and run away to the estate to look for the treasure. Nanna finds them with the help of Johannes and Louise, but soon they discover that they are not the only ones hunting for the treasure in the estate's basement.

The friends discover a secret passage that leads further into an old bunker. Together they move deeper into the depths, but Tania quickly becomes irritated with Louise, who would rather record YouTube videos than find a new way out. The seriousness is revealed when they suddenly find the skeleton of an old German soldier along with a real diamond necklace. Niels' hope of finding the Amber Chamber is strengthened, but can he convince the others to continue?

Unaware that the landowner and his two sons have started hunting them, the friends come to a room full of gold bars - but not everything is as it seems. Johannes saves Nanna from an explosive situation, and Niels must realize that the treasure hunt is no longer a game. The landowners and the two sons are closing in, and Tania must make a dangerous decision to save them.

The situation escalates, and Niels is forced to fire an old flare gun at the landowner and his two sons, who are dangerously approaching the friends. Tania desperately tries to find her way in the darkness underwater and suddenly gets stuck and breaks her foot. Tania can no longer move so quickly, and the six friends have to come up with a new plan to escape the landowner. Nanna and Niels end up in another argument, which has consequences for the unity of the group.

The landowner and his sons have captured Tania, and they question her about Charly's lost shoes. Charly runs barefoot home to the mini-golf course to tell her mother the truth, but she thinks it's another one of his lies. She demands that Charly apologize to the landowner, who surprisingly invites her for tea and lemon moonshine. Inside the bunker, Nanna and Johannes try in vain to avoid the landowner's two sons, while Niels' attempt to save them all ends in complete failure.

The landowner and his two sons have now captured Tania, Johannes and Nanna. Only Louise can save them, but can she find the courage to do so? Charly's many lies lead to house arrest, and he must sneak out to help his friends. Niels has fallen into an old, dark cave, and the treasure chamber is suddenly within reach. But the room is full of traps, and the landowner has caught up with him - Niels must choose between the treasure or the way out.

Once and for all, the friends want to stop the landowner who has escaped with the Amber Room's most precious object: the Fabergé egg. With Johannes behind the wheel of the old rat-catcher car, a wild car chase begins after the landowner and his sons, who have planned to escape in a plane. But an accident puts an end to the car chase, and Nanna must use other horsepower to stop the landowner from escaping.