The fisherwoman Luise Petersen has signed over her fishing cutter to her children. Luise had gone out with her son Erik for years, but he wants to give up fishing and has already found a buyer for the pot. Sister Suntje, on the other hand, does not want to give up cutters, fishing licences and the family tradition. The siblings are at odds. Luise Petersen asks ex-prosecutor Karin Lossow for mediation. Shortly afterwards, Suntje is dead. Karin knows: If she interferes in the work of the Usedom Criminal Investigation Department, there will be trouble with her nephew, homicide investigator Rainer Witt, and his colleague Ellen Norgaard, who is back on duty. Nevertheless, Karin wants to give Luise certainty as to why her daughter had to die.