A young woman is arrested in an Asian shop. She is completely beside herself. Her clothes, hands and face are covered in blood. She is holding a knife in one hand. Did she commit murder? And what about the "Chinese dog" that is said to have seen everything? The Dortmund homicide squad team is initially in the dark. But then the fine gold chain that the young woman is wearing around her neck provides a clue to her identity. A jeweler recognizes the piece of jewelry: he had made the valuable chain several years ago for the Dortmund steel dynasty Haiden family. The suspect is the 25-year-old daughter of the factory owner family. She claims to have killed someone, but can't remember anything. All in all, a murky case with traces from the Ruhr area to China.