Winden was an ordinary German town in which something very rarely happens. However, in 2019, something happened that worried many - two children disappeared. This event horrifies the inhabitants of the town and binds four local families. However, the most interesting thing is that this is not the first time, something similar happened 33 years ago.
Jonas was treated in a mental hospital, and recently he was finally released. The guy is trying to improve his life, and returns to school, where he meets his close friend Bartosz. Around the same time, another guy from Winden named Eric disappears. An investigation begins, led by Ulrich Nielsen. Thirty-three years ago, his brother disappeared, the loss of which the parents of Mads and Ulrich still cannot survive.
The Nielsen children, along with Bartosz and Jonas, go to a cave in the forest where the missing guy had a cache in which he kept drugs. Along the way, they unexpectedly run into Franziska Poppler, who is in the same class as them. Once near the cave, the children hear strange sounds coming from it and run away from there, but Mikkael gets lost along the way.