There is also a possibility you are looking for a specific book by Andrea Camilleri that involves unraveling a complex mystery "thread." Could you please clarify if you are looking for: The book by Santo Piazzese ? A specific Inspector Montalbano story by Andrea Camilleri?
The title (German for "The End of the Thread") is actually a famous Sicilian mystery novel written by Andrea Camilleri's contemporary, the author Santo Piazzese (originally published in Italian as La doppia vita di M. Laurent ). Andrea Camileri Das Ende Des Fadens Commissa...
Andrea Camilleri did not write a book titled "Das Ende des Fadens." There is also a possibility you are looking