(4 episodes)

Jasper Thalheim (Matthias Matschke) aka "Professor T." lectures criminology and criminal psychology at the University of Cologne. On the one hand, he is highly brilliant, but on the other hand he has an equally high deficit of social competence. On top of that, there is his strong need for cleanliness.
One day, his former student Anneliese Deckert (Lucie Heinze) asked him for help in her position as commissioner, T. became an advisor to the Cologne homicide squad.
But working with T. is far from easy. He is absolutely aware of his sharp mind and also uses it to express his opinion very directly. This is especially the case with chief commissioner Rabe (Paul Faßnacht), who feels completely betrayed by T.'s butting in. But he, too, will sooner or later have to recognize that T., in his confused and yet logical way of thinking, is a true expert in his field. Through his new work, T. is confronted with the homicide squad´s boss: Christina Fehrmann (Julia Bremermann). Until a few years ago, she was the love of his life and the only person he ever introduced to his mother (Hedi Kriegkotte). At least until the day she meets the escort lady Tamara (Marie Rönnebeck)...