In the spotlight of an impatient public, Chief Detective Oskar Lindt from Karlsruhe and his team pursue every lead for months in the case of twelve-year-old Patrick, who was found beaten to death in the woods. It is only when the boy's school bag is discovered that the investigation gains momentum. Two beech nuts found in a small bag inside the backpack provide the crucial clue. And slowly, Detective Lindt begins to grasp the full extent of the crime...