Leopold Wallisch, nick-named "Lemming", was fired from the homicide department due to intrigues by his colleague Krotznig. Now he works for a small Viennese private detective agency and spies on potential adulterers. When the Latin teacher Grinzinger is murdered while under Lemming's observation, he gives himself a shove and decides to solve the case himself. "Lemming's First Case", an adaptation of the best-seller by the Austrian author Stefan Slupetzky, promises pure crime comedy.