The high school rector, Max Junghans, who is highly respected in the community, dies in the explosion of a new cell phone mast. For Lena Odenthal and Mario Kopper, the question quickly arises as to why the teacher canceled his "Night Wanderer" tour in the middle of the night and went to the transmission mast. Who sent him there with a text message? The investigations focus on the former demolition expert Georg Schwab, the head of thelocal citizens' initiative against radio masts. Max Junghans was not only responsible for the construction of the transmission mast near Schwab's apartment - he also had a relationship with his 18-year-old daughter Mona Schwab. But Junghan's wife may also benefit from her husband's death. Lena Odenthal and Mario Kopper are also facing a few sleepless nights, and in this case they become night walkers themselves.