The German Federal Police intercepts multiple cell phone conversations between Germany, Damascus, Baghdad, and Grozny concerning terrorist attacks in Western Europe and drug trafficking. Working urgently, the Federal Police and Domestic Intelligence set up a makeshift command center in a small town on the Lower Rhine, where the calls originated. Middle East expert Walther Sembach, punitively transferred from Damascus to Germany, is given the thankless task of identifying the callers. When he gets too close to the truth, he himself becomes a target.