A dark manhunt

Quick intervention is required when this radio message comes in: choking attack on an Uber driver. When the police team Sarah Schräder and Jonas Horder arrive at the scene in downtown Mainz, a man has another man under his control. The situation is completely opaque. The team has to react immediately: It turns out that the man lying on the ground is heavily drunk and very aggressive. He's the one who attacked the Uber driver. His friend holds him. The Uber driver complains of severe pain in his neck. Why the choking attack occurred remains unclear. During the night another radio message comes in: A girl is looking for her friend. Both were attacked and beaten by men on the banks of the Rhine. The girls fled in different directions. Now the worry is great: Where is the girlfriend?