Summary Mechthild Fehrenbach actually only wanted to record a new entry for her video blog. But when she takes a closer look at the recording and discovers that someone on board a ship is writing HELP on the window with lipstick, she calls her daughter Nele. But she is in Hamburg for a training course and does not share Mechthild's suspicion that a crime is behind it. Mechthild is not put off by this, but she has to pull out all the stops until she has convinced her "colleagues" at WaPo-Bodensee that she is following a hot lead. After initial checks by the ship's owner Stephan Hambach and a visit on board the ship, there is initially nothing to indicate a crime. Mechthild was right. Sina Bredel, who has just been released from prison, still has a score to settle with the ship's owner and is threatening to destroy someone's life. While Jakob has his hands full trying to prevent the "Miss Marple of Lake Constance" from further investigations, Sina Bredel's ultimatum is heading for a deadly finale. Mechthild's life is in danger and Max experiences a surprise at Hambach's wife Katrin's house.

• Crime