It is late September, and Anna Kiehl, a student of anthropology and a single mother, does not return from her evening run in the forest. The next morning, she is found dead. She is naked, her throat is cut, and there is a bouquet of poisonous hemlock on her chest.
Police inspector Daniel Trokic is in charge of the investigation, and it leads him to the case of a prominent scientist and specialist in neurochemistry and antidepressants who disappeared eight weeks earlier. Daniel Trokic must get to the killer before he strikes again, but this turns out to be a dangerous pursuit.