A stolen figurehead leads Melanie and Mattes to the restaurant ship "Elbnixe". But landlady Ariane and her daughter Clara seem to have vanished off the face of the earth. When Clara is later admitted to hospital, badly beaten, it raises fresh questions for the officers: who did this to the girl, and why? Were mother and daughter on the run from someone? And how is Ariane? What is certain is that, before her disappearance, she paid the outstanding bills for her restaurant. It seems she wanted to get the restaurant, on the brink of insolvency, back on its feet. So why would she have gone into hiding? The officers discover that, before her disappearance, the landlady had a bank appointment — and on that very day another customer was attacked outside the bank. Did Ariane see something she was not meant to see? What is clear is that the officers of PK 21 must find Ariane before she falls into the hands of whoever is responsible for Clara''s injuries. Meanwhile, Franzi is jealous of her babysitter. She seems perfect, and Franzi fears she may be replaceable. Through the case, however, she comes across photos that cast her babysitter in an entirely different light. Franzi has to make a decision. (Text: ZDF) German premiere: Thursday 14 January 2016, ZDF