Nele and Paul barely manage to pull Helmut Pohl out of the water. He had attacked the sailor Lorenz Haller on his boat. Haller was able to fend off the attack. Pohl ends up in the water and falls so badly that he slips into a coma at the hospital. It soon turns out that the man who suffered the accident is the boat's real owner. Haller had bought it in good faith online—from a scammer. Julia and Jakob discover that the payment went to the account of 19-year-old Mila Simic. But Mila is also a victim. She had fallen in love with Jonas, who was just using her. His real name is Maximilian Hofer. He is known to the police as a violent repeat offender. Mila isn't willing to let the matter rest. She meets with Maximilian. A big mistake. Because Nele and her team are also on the trail of this unscrupulous guy.

Jakob sees Vanessa as the woman of his dreams. But Vanessa is recovered dead from Lake Constance—drowned. Paul wants to immediately remove his colleague from the case due to a conflict of interest. However, the worldly-wise Nele fears Jakob might go it alone and keeps him on the team. He immediately sets his sights on Vanessa's ex-boyfriend, Bastian. Bastian had followed her from Düsseldorf to settle debts from a business venture they'd shared. Bastian claims to have spent the night with the receptionist, Marianne Tillich. What about Yvonne, Vanessa's sister? She lives with her boyfriend Georg in a house by the lake that runs a boat rental business. She would have had to give up that idyllic life and sell the house to pay out Vanessa's share of the inheritance. Yvonne presents the investigators with yet another version of events. She says she wanted to sell the house and move to Spain with her sister—without Georg, but also without Jakob. This sends him into an existential crisis.

A lifeguard who drowns? In the case of Daniel Seeger, knockout drops rendered the head of the local DLRG station incapacitated. Nele and Paul investigate the deceased's professional circle and come across his assistant, Leon Berg. The drone expert and motorcycle enthusiast is clearly playing a double game. Then there's the combative environmentalist Carl Weyrich, who felt disturbed by beachgoers and provoked by Daniel. A motive for murder? The WaPo team realizes it has to change its approach. Because, little by little, more and more victims of knockout drops are turning up—people who nearly drowned. For Nele, the case takes on a personal dimension. Her son Niklas, who's skipping school and wants to move out, finds himself in mortal danger. And the DLRG team also includes Anna, whom Noah knows from school. She's happy with her colleague Yannik. Meanwhile, Nele's mother Mechthild is working on a plan to keep the family together.