Bruno Roth (Manfred Krug) maintains in an old villa in Berlin Lichtenfeld, the Detektivbüro Roth - together with Olga (Eva Maria Bauer), the wife of his deceased brother, her son Uli (Peter Seum) and his girlfriend Ricarda (Ute Willing).

It identifies in cases of industrial espionage, insurance fraud, personal protection, sabotage, drug offenses, legacy hunting or art forgery.

Bruno Roth is a clever, self-assured and profit thoughtful man who accepts only worthwhile cases.

Albert Löffelhardt (Klaus Löwitsch), housed in an old mom-and-pop store and has some parallels to his colleagues television Schimanski.

Egon Fetzer (Heinz Schubert) takes over his shop (episodes 24–35), to bring him finally to success and to found a detective academy.