(Note: This review will include minor spoilers, but nothing earth-shattering.)
I read the summary of the book and was immediately intrigued because it seemed to include so many aspects that sounded absolutely fascinating: a mysterious murder; a diary full of codes and secrets; main characters on the run from deranged killers; and of course, the fairytale king and his fantastic castles. In fact, I'd say that Ludwig II was the hook that drew me in the most - he wasn't someone about whom I knew all that much (okay, actually, I hadn't known anything at all about him), but the tidbits included in the summary piqued my interest and prompted me to start reading as soon as I got my hands on a copy of the book.
To the credit of the book and its author, I found all of the information about the king to be, by far, the best parts of the story. He was someone who came into immense power but soon found himself disillusioned in and disappointed by the goings-on in the world and those who sought power heedless of the cost. He found refuge in turning his dreams into reality, in terms of building his opulent (to the point of sometimes being ostentatious) castles. He was someone for whom it was easy to feel sorry at times, but also someone who could be a petulant child with a frightful temper and ideas that would lead others to reasonably question his sanity. The scheme to depose him ended in tragedy, of course, with not only his death but also that of the doctor who declared him insane. The exploration of the various conspiracies regarding their deaths - he supposedly killed the doctor and then himself, but the doctor's pocket watch stopped almost 1.5 hours after the king's; the idea of him drowning himself though the water was only waist-deep and there wasn't any water found in his lungs; the witness(es) who heard gunshot(s); the portrait of his body showing what looks like dried blood near his mouth; and the list goes on and on - was incredibly interesting and I think that Oliver Potzsch did a wonderful job of exploring the myriad theories as fully as one could in a work of fiction.
Along those lines, I have to say that my favorite of the book was actually the glossary for conspiracy theorists that Mr. Potzsch included at the end of the book: it included entries about every historical figure, event, and term surrounding Ludwig II, his death, his castles, and his followers. In fact, this captured my interest so much that I think I'll be looking for nonfiction works about the fairytale king so that I can learn more about him, and I think that is a testament to the skillful job the author did in really delving into the intrigue of that subject matter.
Unfortunately, that's where my enthusiasm for the book (mostly) ends. The whole running-from-deranged-killers bit had its moments of suspense, and the way that the mystery played out did have one decent twist and compelled me to want to read on to find out exactly how it would be resolved. So, those were two pretty big pluses. However, the main characters - Steven and Sara - I found to be little more than ciphers. They were simply there to keep things going and explain things, but their dialogue was clunky and ran much more toward exposition than any kind of conversation that actual people would have. I suppose a relationship was inevitable, but that particular "journey" was painfully obvious and not so well-written, since they went from constant bickering and Steven being annoyed by her, to kissing and then the declarations of love started flying.
The villains of the piece were cartoonish, at best, and suffered from the desire to talk endlessly to their intended victims rather than carrying out their plans with anything resembling deliberation and timeliness.
The overall pace was on the slow side, the length could have (and should have) been edited down a bit, and some of the passages were clunky, which can be attributed to the translation. Those issues, in and of themselves, weren't deal breakers, but they certainly didn't help matters. Further, as other reviewers have mentioned, the action was propelled forward not by brain power or an organic progression of events, but by a never-ending series of very-forced coincidences. The code-breaking - which could have been immensely entertaining and interesting - was actually kind of boring and repetitive. Also, I have to say that the super-huge secret that people were willing to kill for? Was something that readers could guess from very, very early on in the piece. Also, from the beginning, Steven had a mysterious connection with the diary that he didn't understand until someone clued him in near the end. The problem? That, too, was relatively easy to figure out.
All in all, I very much appreciated all of the information about the king, his death, his castles, and the conspiracy theories, and there was enough intrigue to keep me turning the pages until the very end. However, it was very slow-going at several points, and when I couldn't find anything in the main characters to care about, it made the reading much more of a chore than it otherwise would have been. Maybe the story would have been better served had the author removed the modern day aspects entirely and focused solely on Ludwig II and his death. Since that wasn't the case, though, I can say that I would recommend the book to those with any interest in the historical subject matter and Potzsch's fictional take on some aspects thereof, but anyone with his or her heart set on a tale filled with pulse-pounding suspense where the pages just fly by may want to temper those expectations before deciding to give this one a read.