The discovery of the corpse of an Eastern European man leads inspector Ellen Lucas to the construction environment in Regensburg, where she encounters blatant abuses. She calls on her entire team to clarify the matter and puts the public prosecutor to the test. The unexpected "by-catch" by customs officials during a night-time traffic check is tough. At the border to the Czech Republic, the border officials noticed a car. The view through the thermal imaging camera shows only two occupants, although apparently three people are sitting in the car. When the officers stop the car, two men flee, the third is dead, presumably he was pierced by an iron bar. He has no ID with him, but the car is registered to a construction company. Detective Lucas and her team begin their investigation.
The new Regensburg public prosecutor, Stefan Walch, is also very interested in the case. He has long had Walter-Maria Bäucker, the head of the company, in his sights for illegal activities and senses his chance to finally get him. While Lucas and Walch try to penetrate the exploitative system with which the Regensburg construction tycoon Bäucker secures a constant flow of well-trained workers from Eastern Europe, Lucas' superior Boris Noethen looks skeptically at the exuberant energy of the "new man" in the team. But Ellen Lucas enjoys the fresh wind. With Walch's backing, she can investigate faster and in a more unconventional way, and she succeeds in infiltrating her colleague Tom as a worker on the construction site.