Nine dead on the Brocken, and everything points to murder. A group of students sets out for the Brocken liberation on the first Sunday of Advent in 1989. The next day, they are all dead. Something has evidently driven them out of their tent in freezing temperatures. Three liaison officers from the BKA are investigating in the border area, as is Tomas Düvel, one of the most capable detectives in the GDR. They discover that the tent was cut from the inside, a shoe print does not seem to belong to the students, and the sweater of one victim is radioactively contaminated. However, the gruesome truth behind it all only comes together piece by piece...