What began as a romantic trip to Mainau ends in disaster for Christine Keppler and Matthias Bruhns. Within minutes, their pedal boat filled with water. For Bruhns, who is physically unwell, the distance to shore is too far.

Andrè Malik is notorious for his thefts around Lake Constance. Paul explains to Nele that Malik is wanted by the police when a distraught mother bursts into the station. Mira Baader reports that her 16-year-old daughter, Leonie, hasn't returned from her morning stand-up paddleboarding trip. Almost immediately, a kidnapper calls her cell phone, demanding that she keep the police out of it.

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.