Bruno Roth (Manfred Krug) runs the Roth detective agency in an old villa in Berlin-Lichterfelde - together with Olga (Eva Maria Bauer), his brother's wife, their son Uli (Peter Seum) and his girlfriend Ricarda (Ute Willing). He investigates cases of industrial espionage, insurance fraud, personal security, sabotage, narcotics offences, inheritance fraud or art forgery. Bruno Roth is a clever, self-confident and profit-minded man who only takes on worthwhile cases. The Duisburg detective agency Löffelhardt, on the other hand, is different. Albert Löffelhardt (Klaus Löwitsch) lives in an old corner shop. Because he constantly has to fight for his existence, he takes on every case. When the regions of the two detective agencies overlap, they are sometimes forced to work together, even though this often leads to conflicts.