An unforgettable history lesson... for them and for you. Mattie Engel is a rising star at Private Berlin and thinks she's seen the worst of humanity during her previous stint with the Berlin police. That is, until Chris, her colleague and, until recently, her fiancé, is found dead, gruesomely murdered in a disused slaughterhouse outside the city. The slaughterhouse is found to be full of bodies. Just as Private begins their investigation, the building explodes, wiping out all evidence of the crimes and nearly costing Mattie and her team their lives. Mattie soon discovers that a masked killer is picking off Chris's childhood friends one by one, destroying all traces. But who is so desperate to bury the past? What is the truth behind the slaughterhouse? And will Mattie become the killer's next victim?