Summary Canoe polo is a sport for well-trained daredevils like Paul Schott. When he takes part in a tournament on Lake Constance, his colleague Julia and Nele cheer him on with their children Johanna, Niklas and his friend Josh. But the enthusiasm turns to horror when an opposing player floats dead, headfirst, in his kayak... Paul, of all people, now blames himself badly for having attacked his opponent hard beforehand. However, the forensic medicine points to a new clue: the dead man had poison in his drinking bottle, which manipulates his sense of balance. But the motive is missing: did Noah's friend Josh really want to poison the math teacher because of the threat of bad grades? There are also lots of dead fish floating in Lake Constance. Nele soon identifies the solar module manufacturer Yannik Sattmann as the culprit. It is piquant that the committed canoe polo player is arguing loudly with Arne Holtkamp in the club. But a completely different abyss opens up for Nele. Their daughter Johanna is going to New Zealand for a year. Niklas is therefore already looking forward to life as an "only child".

• Crime