Due to the sudden information on the arrest of phantom thief Mubou, the great detective Akitsu Shouichirou and his assistant Komura Nozomi head to Natsuhara Hotel, where Mubou is held captive, to gather with the other 2 well-known members of the '3 great detectives'. Being indwelled by Akarumi, the hitodenashi of earthquakes and dreams, the Hotel is also called Mukyou Hotel due to the week of dreams happening once a year when the hotel itself picks out a certain number of customers and sends them into its dream realm to experience the unusual free of charge. To be recognised as Akitsu's offical assistant, Nozomi has to prove his abilities as this year's 'hotel detective' during the week of dreams and it doesn't take long until the first corpse turns up...
One hell of a read. This volume includes and combines mystery, fantasy and sci-fi altogether in a well-balanced way which results in a very lush setting and a brilliantly constructed story. Due to this though, there isn't as much focus on the murder case and investigation in contrast to the first volume of this series but on the other hand the reader is served with an even more enthralling storyline and even more focus on the characters this time. Which in my opinion makes this book at least as enjoyable as the first one, but since this time the focus lies so much on aspects like characters and themes (which are also taken to an even deeper level this time) that aim at a more personal sphere, it's difficult to say if anyone else or at least readers of the first volume could still enjoy this series.
As for the reasoning aspect... I'm not really sure what to say. Since the whole setting works on the supernatural sphere this time the boundaries for the reader possibly were a bit to overt and vague and while you could figure out what happened it's not like lots of other explanations wouldn't have sufficed just as well since the conditions and factors weren't that clear anyway. Personally I thought that this didn't really matter since the focus of this volume certainly wasn't on the reasoning but more on the level of guessing which was in this case making the book just as much a page-turner as the first volume.
This works because of another really strong aspect of this book, the narration. Instead of focusing on Nozomi as in the first book, the narration constantly switches between many characters with only vague information on them at the beginning so the book left me guessing over the whole reading process how all the pieces would fit into the puzzle as a whole in the end. And in fact all the characters turned out to play roles necessary for the picture to be complete. The result is an awesome finale where all pieces come together, all character development pays out and the themes are thickened and deepened to the point where you can no longer say who is right or wrong.
This way of narrating the whole story like a puzzle makes this an awesome mystery book even with lesser focus on the murder case itself so all in all I would recommend this to fans of the first volume who don't mind the author elaborating on the supernatural elements and themes already touched on before and those looking for a good mystery story with fantasy and sci-fi aspects that keeps you excited and guessing until the big finale. Keep in mind though that it doesn't make any sense to begin with this novel without knowing the first one since even though many aspects from the previous volume are more or less summed up at the beginning it just happens too often that previous events are mentioned and you just have to know certain character traits and developments from the first novel or otherwise I can't imagine anyone really understanding the main characters. Furthermore in the very last chapter the reader is served with a forecast for the next volume involving a character from the first one which is awesome for those who are clued up and can really feel this becoming a series and are therefore also left with a sort of cliffhanger anticipating the next volume impatiently... but if you don't know what the heck is going on this will confuse you even more so just read the first volume as well since that one is just as good while also being a fairly different experience.