After weeks of searching, 15-year-old Nicole Ulmer is found dead in the woods, apparently the victim of a violent crime. Inspector Klara Blum and Kai Perlmann learn from the devastated father, Klaus Ulmer, that Nicole had a crush on the handsome Holger Bucheck, for whose family she worked as a babysitter. Not only Klaus, but also his brothers Herbert and Peter Ulmer are convinced that Bucheck is responsible for Nicole's death. Herbert's daughter Jessica, Nicole's best friend, refuses to tell Klara anything about Bucheck or Nicole's other friends. In fact, HolgerBucheck stopped near the crime scene. But while Klara and Perlmann are investigating him, Holger Bucheck disappears without leaving any news or traces. And Klara is receiving more and more anonymous messages with mysterious clues.
She quickly finds out that Jessica must be the sender. Jessica also seems to be moving further and further away from the close family community of the Ulmers. Convinced that Jessica is the key to the mystery of Nicole's death and Bucheck's disappearance, Klara tries to interpret the mysterious signs.