Jakob's daughter Tammy is gone! She just took off in a rubber dinghy. The search for her leads to two outcomes: Jakob must reconnect with his daughter—a process in which Mechthild offers both advice and practical support—and the WaPo must investigate the violent death of a wife and mother who is found dead in Lake Constance, right next to the spot where Tammy fled.

Jakob is the first to sense the danger. Tammy's mother, Sonja, has never let her daughter down. Now she's ignoring Jakob's call, even though she was supposed to have been back at Villa Fehrenbach 24 hours ago. Of all people, Julia supports her ex-boyfriend Jakob in his desire to track Sonja's cell phone, while Nele is still hesitating. A visit to the art expert and collector Ruben von Wallersleben reveals the unsettling fact that, until recently, Sonja had been restoring an Otto Dix painting—one that has just been discovered under strange circumstances and is worth millions.

It's the perfect evening: As Julien Bakker speeds across Lake Constance in a motorboat with his beautiful companion after a visit to the lakeside terraces, they're both tipsy and have eyes only for each other. They hear the desperate cries of a rubber boat driver too late. Because he doesn't want his affair with his companion, Flora Fitz, to be exposed—and because he's also under the influence of alcohol—Bakker flees the scene of the crime. There's no trace of the rubber boat's driver. He keeps the accident a secret from his wife, Annika. Instead, he finds a blackmail letter on his car the next morning…