In a forest on the outskirts of Vienna, a married couple arriving at their suburban home finds a naked, emaciated girl. Her entire back is covered with tattoos with motifs from Dante's Inferno. The police manage to find out that this is eleven-year-old Clara, who disappeared a year ago. But the girl stubbornly remains silent about the past twelve months. Meanwhile, a young employee of the Munich police, Sabine Nemez, begins training on a course for highly talented young personnel. Her teacher is the experienced Dutch profiler Maarten S. Sneijder. The essence of his teaching method is that he solves unsolved crimes with students. Soon Sabina, together with Sneijder, is immersed in the investigation of three terrible cases, which only at first glance have nothing in common. And when a connection is made with the kidnapping of that same girl in Vienna, the boundaries between theory and practice are completely blurred...