Steven Lukas, an antiquarian from Munich, discovers an old book on his shelves that he has never seen before. Soon, he realizes that it is the diary of a close confidant of Ludwig II, the assistant to the royal court physician Max Schleiss von Loewenfeld. The book, over a hundred years old, is written in a secret shorthand that Lukas can only decipher bit by bit. This astonishing find could reveal the true circumstances surrounding Ludwig II's death! However, it seems that various parties are interested in preventing the publication of the diary. And a fanatic is willing to go to great lengths. Together with art detective Sara Lengfeld, Lukas embarks on a quest to uncover the mystery—a journey that takes them to all the castles of the fairy tale king.