Martin Kuhlmann and his team have to solve the murder of an unknown man who was presumably employed as an illegal worker and died in an industrial accident. In addition, they find a restorer dead who was apparently involved in criminal business.
However, he and his colleagues experience further surprises when another body is found. Once again they are confronted with the old, already closed cases of Jo Sehler and Oleg Sokolow.
By chance, Martin's son Gero, of all people, leads them on the right track and even more dead bodies.