The main character in this series of suspense books is private detective Patrick Reich. From his office he has a beautiful view of the city of Kassel, the scene where his cases happen. Where is Cornelia Sonnenschein? She had intentions to write her will but now it has disappeared without any trace. His family is extremely concerned and Private Detective Reich has taken the case. These little detective novels are illustrated with many explanations of words, information about the country, interesting Internet addresses, puzzles and exercises.