After 280 episodes starring popular TV-Star Peter Lindburg as "Kommissar Kämpfer", his award-winning cop series "Blaulicht" ('Cop car siren') is shut-down due to sinking viewer numbers. Shattered Lindburg, who swapped birth name Schmidt for his Thüringen native town as artistic pseudonym, returns there, still the home of his first love Sabine Arnhold, hoping a script specifically written for him may enable a comeback. Unexpectedly, Lindburg witnesses during an after-dark park walk shadows behind a home window, according to his 'experienced eye' a brutal murder by the inhabitant: state attorney Dr. Eugen von Wangenheim, whom police commissioner Biehl dares not even suspect, turning on the 'TV lunatic' instead, to no avail. The press finds out and has a field day, notably boulevard-reporter Caroline Bächle, whom Lindburg is delighted to by interviewed by. Mike Häusl, who played his "Blaulicht"-sidekick Conny, reluctantly joins his now private investigation, while their agent drops the ball and the police won't act until they bring solid evidence against the DA and his senile aunt Cäcilie. First Lindeberg stumbles upon a fitting duped corpse, later on dubious gardening clues.