Three people waiting at a bus stop in a suburb of Munich are shot dead when an unknown killer runs amok from a place of concealment. The culprit is identified and arrested with surprising speed, and he quickly confesses. Chief Supt Kreiner (Ilona Grübel) is pleased that the case has been cleared up - but the detectives in SOKO Munich are not at all happy. In fact, in direct contravention of orders, Arthur Bauer (Gerd Silberbauer) and his team continue to investigate the case, and soon they have good reason to suppose that this was not a random killing at all. One of these people was the target from the very beginning. But which one? And above all - why?