Tanja Sorg owns an Opel Nakkita GTC, a chic girls' coupe, tuned at the factory and with its paint job an absolute one-off. Hans Burgmeister, a moderately successful traveling salesman, drives too fast into a densely populated residential area in Porta Westfalica, loses control of his SUV and rams Tanja's beloved Nakky. Two days later he is dead, run over in a field and all the evidence points to Nakky as the murder weapon. This is the beginning of an absurd series of murders in which detective inspector Charlotte Bauer has a lot to gnaw on. Absurd, because you can kill someone with a Nakkita, but you certainly can't run them over, because the coupes of the GTC series with their sports chassis are much too low over the road for that. The victims of the murders, however, have tire marks on their faces, and in the courtyard of Nadja Pfeifer's workshop there are literally piles of damaged cars and wrecks of this type, which after the respective accidents are observed undamaged by witnesses during the murders.