Babs Sprenger, a successful businesswoman who lives alone in a spacious apartment in Fürth, was active on various dating sites under an assumed name until a few months ago. She celebrated her birthday alone with her colleague Theresa Hein. The next day, Babs Sprenger was dead. Stabbed with a sushi knife that the police found in the dishwasher, thoroughly cleaned. The knife was Theresa's gift to Babs. How did it become a deadly weapon? What happened that evening? Even after Theresa's confession, the question of why remains unanswered. Voss and Ringelhahn suspect that the truth lies much deeper. What could Theresa be hiding?